{ "document": { "category": "csaf_base", "csaf_version": "2.0", "distribution": { "tlp": { "label": "WHITE" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings." } ], "publisher": { "category": "coordinator", "contact_details": "cert@ncsc.nl", "name": "National Cyber Security Centre", "namespace": "https://www.ncsc.nl/" }, "title": "CVE-2026-27204", "tracking": { "current_release_date": "2026-03-26T20:18:58.298951Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-27204", "initial_release_date": "2026-02-24T21:39:49.397513Z", "revision_history": [ { "date": "2026-02-24T21:39:49.397513Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (8).| CWES updated (1)." }, { "date": "2026-02-24T21:39:54.982400Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-02-24T22:32:30.339836Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (7).| CWES updated (1)." }, { "date": "2026-02-24T22:32:38.626670Z", "number": "4", "summary": "NCSC Score updated." }, { "date": "2026-02-24T22:38:55.775034Z", "number": "5", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (4).| References created (7).| CWES updated (1)." }, { "date": "2026-02-24T22:38:57.335443Z", "number": "6", "summary": "NCSC Score updated." }, { "date": "2026-02-25T00:43:46.267957Z", "number": "7", "summary": "Source created.| CVE status created. (valid)" }, { "date": "2026-02-25T06:43:26.987206Z", "number": "8", "summary": "Description created for source." }, { "date": "2026-02-25T07:35:32.581817Z", "number": "9", "summary": "NCSC Score updated." }, { "date": "2026-02-25T11:02:19.356123Z", "number": "10", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (31).| Products created (4).| References created (9).| CWES updated (1)." }, { "date": "2026-02-25T11:02:23.878941Z", "number": "11", "summary": "NCSC Score updated." }, { "date": "2026-02-25T12:27:57.044977Z", "number": "12", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (2).| Product Identifiers created (1).| Product Remediations created (2).| References created (9).| CWES updated (1).| Vendor_assessment created." }, { "date": "2026-02-25T12:28:00.995262Z", "number": "13", "summary": "NCSC Score updated." }, { "date": "2026-02-25T15:14:03.123013Z", "number": "14", "summary": "Source created.| CVE status created. (valid)| EPSS created." }, { "date": "2026-02-25T15:14:12.323472Z", "number": "15", "summary": "NCSC Score updated." }, { "date": "2026-02-25T15:28:58.827709Z", "number": "16", "summary": "CVSS created.| Products connected (4).| Product Identifiers created (4)." }, { "date": "2026-02-25T15:29:03.688329Z", "number": "17", "summary": "NCSC Score updated." }, { "date": "2026-02-26T07:27:38.767654Z", "number": "18", "summary": "NCSC Score updated." }, { "date": "2026-02-27T20:39:34.287309Z", "number": "19", "summary": "References created (2).| CWES updated (1)." }, { "date": "2026-02-27T20:39:42.068412Z", "number": "20", "summary": "NCSC Score updated." }, { "date": "2026-02-27T21:39:02.950286Z", "number": "21", "summary": "Unknown change." }, { "date": "2026-03-02T19:23:08.413344Z", "number": "22", "summary": "Products removed (31)." }, { "date": "2026-03-02T19:23:10.713201Z", "number": "23", "summary": "NCSC Score updated." }, { "date": "2026-03-03T14:18:29.874457Z", "number": "24", "summary": "Products connected (31)." }, { "date": "2026-03-03T14:18:36.010192Z", "number": "25", "summary": "NCSC Score updated." }, { "date": "2026-03-20T09:42:01.875604Z", "number": "26", "summary": "Source connected.| CVE status created. (valid)| EPSS created." }, { "date": "2026-03-20T09:42:05.970659Z", "number": "27", "summary": "NCSC Score updated." }, { "date": "2026-03-26T18:47:43.106141Z", "number": "28", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (5).| Products connected (1).| References created (11).| CWES updated (1)." }, { "date": "2026-03-26T18:47:48.959557Z", "number": "29", "summary": "NCSC Score updated." } ], "status": "interim", "version": "29" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/1", "product": { "name": "vers:rpm/1", "product_id": "CSAFPID-2914823", "product_identification_helper": { "cpe": "cpe:/a:redhat:connectivity_link:1" } } } ], "category": "product_name", "name": "Red Hat Connectivity Link 1" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:rpm/unknown", "product": { "name": "vers:rpm/unknown", "product_id": "CSAFPID-5194593" } } ], "category": "product_name", "name": "wasm-shim-rhel9" } ], "category": "product_family", "name": "Red Hat Connectivity Link 1" } ], "category": "vendor", "name": "Red Hat" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/24.0.6", "product": { "name": "vers:unknown/24.0.6", "product_id": "CSAFPID-5918968" } }, { "category": "product_version_range", "name": "vers:unknown/36.0.6", "product": { "name": "vers:unknown/36.0.6", "product_id": "CSAFPID-5918969" } }, { "category": "product_version_range", "name": "vers:unknown/40.0.4", "product": { "name": "vers:unknown/40.0.4", "product_id": "CSAFPID-5918964" } }, { "category": "product_version_range", "name": "vers:unknown/<24.0.6", "product": { "name": "vers:unknown/<24.0.6", "product_id": "CSAFPID-5918970" } }, { "category": "product_version_range", "name": "vers:unknown/>=25.0.0|<36.0.6", "product": { "name": "vers:unknown/>=25.0.0|<36.0.6", "product_id": "CSAFPID-5918971" } }, { "category": "product_version_range", "name": "vers:unknown/>=37.0.0|<40.0.4", "product": { "name": "vers:unknown/>=37.0.0|<40.0.4", "product_id": "CSAFPID-5918972" } } ], "category": "product_name", "name": "cargo/wasmtime" } ], "category": "vendor", "name": "bytecodealliance" }, { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<24.0.6", "product": { "name": "vers:unknown/<24.0.6", "product_id": "CSAFPID-5700061", "product_identification_helper": { "cpe": "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*" } } }, { "category": "product_version_range", "name": "vers:unknown/>=25.0.0|<36.0.6", "product": { "name": "vers:unknown/>=25.0.0|<36.0.6", "product_id": "CSAFPID-5700062", "product_identification_helper": { "cpe": "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*" } } }, { "category": "product_version_range", "name": "vers:unknown/>=37.0.0|<40.0.4", "product": { "name": "vers:unknown/>=37.0.0|<40.0.4", "product_id": "CSAFPID-5700063", "product_identification_helper": { "cpe": "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*" } } }, { "category": "product_version_range", "name": "vers:unknown/>=41.0.0|<41.0.4", "product": { "name": "vers:unknown/>=41.0.0|<41.0.4", "product_id": "CSAFPID-5699782", "product_identification_helper": { "cpe": "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*" } } }, { "category": "product_version_range", "name": "vers:unknown/cranelift-v0.60.0", "product": { "name": "vers:unknown/cranelift-v0.60.0", "product_id": "CSAFPID-3621837" } }, { "category": "product_version_range", "name": "vers:unknown/cranelift-v0.61.0", "product": { "name": "vers:unknown/cranelift-v0.61.0", "product_id": "CSAFPID-3621838" } }, { "category": "product_version_range", "name": "vers:unknown/cranelift-v0.69.0", "product": { "name": "vers:unknown/cranelift-v0.69.0", "product_id": "CSAFPID-3621839" } }, { "category": "product_version_range", "name": "vers:unknown/filecheck-v0.0.1", "product": { "name": "vers:unknown/filecheck-v0.0.1", "product_id": "CSAFPID-3621840" } }, { "category": "product_version_range", "name": "vers:unknown/v0.12.0", "product": { "name": "vers:unknown/v0.12.0", "product_id": "CSAFPID-3621841" } }, { "category": "product_version_range", "name": "vers:unknown/v0.16.0", "product": { "name": "vers:unknown/v0.16.0", "product_id": "CSAFPID-3621842" } }, { "category": "product_version_range", "name": "vers:unknown/v0.17.0", "product": { "name": "vers:unknown/v0.17.0", "product_id": "CSAFPID-3621843" } }, { "category": "product_version_range", "name": "vers:unknown/v0.18.0", "product": { "name": "vers:unknown/v0.18.0", "product_id": "CSAFPID-3621844" } }, { "category": "product_version_range", "name": "vers:unknown/v0.19.0", "product": { "name": "vers:unknown/v0.19.0", "product_id": "CSAFPID-3621845" } }, { "category": "product_version_range", "name": "vers:unknown/v0.20.0", "product": { "name": "vers:unknown/v0.20.0", "product_id": "CSAFPID-3621846" } }, { "category": "product_version_range", "name": "vers:unknown/v0.21.0", "product": { "name": "vers:unknown/v0.21.0", "product_id": "CSAFPID-3621847" } }, { "category": "product_version_range", "name": "vers:unknown/v0.22.0", "product": { "name": "vers:unknown/v0.22.0", "product_id": "CSAFPID-3621848" } }, { "category": "product_version_range", "name": "vers:unknown/v0.23.0", "product": { "name": "vers:unknown/v0.23.0", "product_id": "CSAFPID-3621849" } }, { "category": "product_version_range", "name": "vers:unknown/v0.24.0", "product": { "name": "vers:unknown/v0.24.0", "product_id": "CSAFPID-3621850" } }, { "category": "product_version_range", "name": "vers:unknown/v0.25.0", "product": { "name": "vers:unknown/v0.25.0", "product_id": "CSAFPID-3621851" } }, { "category": "product_version_range", "name": "vers:unknown/v0.26.0", "product": { "name": "vers:unknown/v0.26.0", "product_id": "CSAFPID-3621852" } }, { "category": "product_version_range", "name": "vers:unknown/v0.27.0", "product": { "name": "vers:unknown/v0.27.0", "product_id": "CSAFPID-3621853" } }, { "category": "product_version_range", "name": "vers:unknown/v0.28.0", "product": { "name": "vers:unknown/v0.28.0", "product_id": "CSAFPID-3621854" } }, { "category": "product_version_range", "name": "vers:unknown/v0.29.0", "product": { "name": "vers:unknown/v0.29.0", "product_id": "CSAFPID-3621855" } }, { "category": "product_version_range", "name": "vers:unknown/v0.30.0", "product": { "name": "vers:unknown/v0.30.0", "product_id": "CSAFPID-3621856" } }, { "category": "product_version_range", "name": "vers:unknown/v0.31.0", "product": { "name": "vers:unknown/v0.31.0", "product_id": "CSAFPID-3621857" } }, { "category": "product_version_range", "name": "vers:unknown/v0.32.0", "product": { "name": "vers:unknown/v0.32.0", "product_id": "CSAFPID-3621858" } }, { "category": "product_version_range", "name": "vers:unknown/v0.33.0", "product": { "name": "vers:unknown/v0.33.0", "product_id": "CSAFPID-3621859" } }, { "category": "product_version_range", "name": "vers:unknown/v0.34.0", "product": { "name": "vers:unknown/v0.34.0", "product_id": "CSAFPID-3621860" } }, { "category": "product_version_range", "name": "vers:unknown/v0.35.0", "product": { "name": "vers:unknown/v0.35.0", "product_id": "CSAFPID-3621861" } }, { "category": "product_version_range", "name": "vers:unknown/v24.0.0", "product": { "name": "vers:unknown/v24.0.0", "product_id": "CSAFPID-3752405" } }, { "category": "product_version_range", "name": "vers:unknown/v24.0.1", "product": { "name": "vers:unknown/v24.0.1", "product_id": "CSAFPID-3752406" } }, { "category": "product_version_range", "name": "vers:unknown/v24.0.2", "product": { "name": "vers:unknown/v24.0.2", "product_id": "CSAFPID-3752407" } }, { "category": "product_version_range", "name": "vers:unknown/v24.0.3", "product": { "name": "vers:unknown/v24.0.3", "product_id": "CSAFPID-3752408" } }, { "category": "product_version_range", "name": "vers:unknown/v24.0.4", "product": { "name": "vers:unknown/v24.0.4", "product_id": "CSAFPID-5184645" } }, { "category": "product_version_range", "name": "vers:unknown/v24.0.5", "product": { "name": "vers:unknown/v24.0.5", "product_id": "CSAFPID-5702046" } }, { "category": "product_version_range", "name": "vers:unknown/v41.0.0", "product": { "name": "vers:unknown/v41.0.0", "product_id": "CSAFPID-5480178" } }, { "category": "product_version_range", "name": "vers:unknown/v41.0.1", "product": { "name": "vers:unknown/v41.0.1", "product_id": "CSAFPID-5702047" } }, { "category": "product_version_range", "name": "vers:unknown/v41.0.2", "product": { "name": "vers:unknown/v41.0.2", "product_id": "CSAFPID-5702048" } }, { "category": "product_version_range", "name": "vers:unknown/v41.0.3", "product": { "name": "vers:unknown/v41.0.3", "product_id": "CSAFPID-5702049" } } ], "category": "product_name", "name": "wasmtime" } ], "category": "vendor", "name": "Bytecode Alliance" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-27204", "cwe": { "id": "CWE-770", "name": "Allocation of Resources Without Limits or Throttling" }, "notes": [ { "category": "description", "text": "### Impact\n\nWasmtime's implementation of WASI host interfaces are susceptible to guest-controlled resource exhaustion on the host. Wasmtime did not appropriately place limits on resource allocations requested by the guests. This serves as a Denial of Service vector where a guest can induce a range of crashing behaviors on the host such as:\n\n* Allocating arbitrarily large amounts of host memory.\n* Causing an allocation failure on the host, which in Rust defaults to aborting the process.\n* Causing a panic on the host due to over-large allocations being performed.\n* Cause degredation in performance of the host by holding excessive host memory alive.\n\nWasmtime's [security bug policy](https://docs.wasmtime.dev/security-what-is-considered-a-security-vulnerability.html) considers all of these behaviors a security vulnerability. Wasmtime's implementation of WASI has a number of different ways that resource exhaustion could happen, and fixing any one of them is insufficient from solving this vulnerability. A number of individual issues are grouped within this advisory and as a whole represent the known ways that guests can exhaust resources on the host.\n\nAn example of guest-controlled resource exhaustion within Wasmtime's implementation of WASI is guests could repeatedly allocate handles to themselves without limit. Some APIs also caused the host to perform a guest-controlled-sized allocation of a buffer on the host for I/O operations. Other APIs could force the host to buffer arbitrary amounts of data for the guest. Finally the guest could hand arbitrarily large allocations from itself to the host which could cause the host to perform an arbitrarily sized copy of memory which in some situations could result in quadratically sized allocations.\n\nWasmtime's implementations of WASIp1 and WASIp2 are affected by this vulnerability. Any host API modeled with the Component Model (or WIT) which operates on a `string` or `list` type is also affected. Not all WIT and WASI APIs are affected by this issue, but that's more of an exception so it's recommended for all embedders to consider themselves affected.\n\nTo address this issue a number of mitigations are being applied to limit the behavior of a guest in WASI. All of these mitigations manifest in the form of a limit of some kind applied to various situations, and as such all of these mitigations are backwards-incompatible as they run the risk of breaking preexisting programs. To address this all backports to previous stable releases have these limits tuned to overly-large values. This ensures that preexisting guests do not break while still providing embedders the knobs to prevent this DoS vector as well. The limits added to Wasmtime are:\n\n* `-Smax-resources=N` or `ResourceTable::set_max_capacity` - the maximum number of resources that a guest is allowed to allocate for itself.\n* `-Shostcall-fuel=N` or `Store::set_hostcall_fuel` - the maximum amount of data that the guest may copy to the host in a single function call.\n* `-Smax-random-size=N` or `WasiCtxBuilder::max_random_size` - the maximum size of the return value of `get-random-bytes` and `get-insecure-random-bytes` in the `wasi:random` implementations.\n* `-Smax-http-fields-size=N` or `WasiHttpCtx::set_max_fields_size` - the maximum size of headers for an HTTP request/response.\n\nThese settings are equally applicable to both WASIp1 and WASIp2. Wasmtime 41.0.x and prior previously did not limit these settings and the knobs being released are set to very large values by default to avoid any breaking behavior. Embedders will need to proactively tune these knobs as appropriate for their embeddings. The default settings in the unreleased Wasmtime 42.0.0 are 1M for max resources, 128MiB for hostcall fuel, 64MiB for max-random-size, and 32KiB for http fields size. Tuning is not expected for Wasmtime 42.0.0+.\n\nHosts/embedders affected by this issue are encouraged to audit and double-check their own host APIs they have implemented to see whether they are affected by this issue as well. The `-Shostcall-fuel` setting is intended to be a relatively coarse fix for many possible issues by limiting the amount of data for all host APIs at once, so many embedders may not need to take further action beyond updating Wasmtime and configuring it appropriately (if not updating to 42.0.0). Embedders should audit to see, however, if the guest is able to force the host to allocate on its behalf and ensure that the allocation is limited or tracked somehow.\n\n### Patches\n\nWasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0 have all been released with the fix for this issue. These versions do not prevent this issue in their default configuration to avoid breaking preexisting behaviors. All versions of Wasmtime have appropriate knobs to prevent this behavior, and Wasmtime 42.0.0-and-later will have these knobs tuned by default to prevent this issue from happening.\n\n### Workarounds\n\nThere are no known workarounds for this issue without upgrading. Embedders are recommended to upgrade and configure their embeddings as necessary to prevent possibly-malicious guests from triggering this issue.\n\n### Resources\n\n* [`Store::set_hostcall_fuel`](https://docs.rs/wasmtime/latest/wasmtime/struct.Store.html#method.set_hostcall_fuel)\n* [`ResourceTable::set_max_capacity`](https://docs.rs/wasmtime/latest/wasmtime/component/struct.ResourceTable.html#method.set_max_capacity)\n* [`WasiCtxBuilder::max_random_size`](https://docs.rs/wasmtime-wasi/latest/wasmtime_wasi/struct.WasiCtxBuilder.html#method.max_random_size)\n* [Original PR showing resource exhaustion](https://github.com/bytecodealliance/wasmtime/pull/12599)\n* [Issue about limiting max resource handles per-guest](https://github.com/bytecodealliance/wasmtime/issues/11552)", "title": "github - https://github.com/advisories/GHSA-852m-cvvp-9p4w" }, { "category": "description", "text": "Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.6, 36.0.6, 4.0.04, 41.0.4, and 42.0.0, Wasmtime's implementation of WASI host interfaces are susceptible to guest-controlled resource exhaustion on the host. Wasmtime did not appropriately place limits on resource allocations requested by the guests. This serves as a Denial of Service vector. Wasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0 have all been released with the fix for this issue. These versions do not prevent this issue in their default configuration to avoid breaking preexisting behaviors. All versions of Wasmtime have appropriate knobs to prevent this behavior, and Wasmtime 42.0.0-and-later will have these knobs tuned by default to prevent this issue from happening. There are no known workarounds for this issue without upgrading. Embedders are recommended to upgrade and configure their embeddings as necessary to prevent possibly-malicious guests from triggering this issue.", "title": "nvd - https://nvd.nist.gov/vuln/detail/CVE-2026-27204" }, { "category": "description", "text": "Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.6, 36.0.6, 4.0.04, 41.0.4, and 42.0.0, Wasmtime's implementation of WASI host interfaces are susceptible to guest-controlled resource exhaustion on the host. Wasmtime did not appropriately place limits on resource allocations requested by the guests. This serves as a Denial of Service vector. Wasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0 have all been released with the fix for this issue. These versions do not prevent this issue in their default configuration to avoid breaking preexisting behaviors. All versions of Wasmtime have appropriate knobs to prevent this behavior, and Wasmtime 42.0.0-and-later will have these knobs tuned by default to prevent this issue from happening. There are no known workarounds for this issue without upgrading. Embedders are recommended to upgrade and configure their embeddings as necessary to prevent possibly-malicious guests from triggering this issue.", "title": "cveprojectv5 - https://www.cve.org/CVERecord?id=CVE-2026-27204" }, { "category": "description", "text": "Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.6, 36.0.6, 4.0.04, 41.0.4, and 42.0.0, Wasmtime's implementation of WASI host interfaces are susceptible to guest-controlled resource exhaustion on the host. Wasmtime did not appropriately place limits on resource allocations requested by the guests. This serves as a Denial of Service vector. Wasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0 have all been released with the fix for this issue. These versions do not prevent this issue in their default configuration to avoid breaking preexisting behaviors. All versions of Wasmtime have appropriate knobs to prevent this behavior, and Wasmtime 42.0.0-and-later will have these knobs tuned by default to prevent this issue from happening. There are no known workarounds for this issue without upgrading. Embedders are recommended to upgrade and configure their embeddings as necessary to prevent possibly-malicious guests from triggering this issue.", "title": "debian - https://security-tracker.debian.org/tracker/CVE-2026-27204" }, { "category": "description", "text": "Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.6, 36.0.6, 4.0.04, 41.0.4, and 42.0.0, Wasmtime's implementation of WASI host interfaces are susceptible to guest-controlled resource exhaustion on the host. Wasmtime did not appropriately place limits on resource allocations requested by the guests. This serves as a Denial of Service vector. Wasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0 have all been released with the fix for this issue. These versions do not prevent this issue in their default configuration to avoid breaking preexisting behaviors. All versions of Wasmtime have appropriate knobs to prevent this behavior, and Wasmtime 42.0.0-and-later will have these knobs tuned by default to prevent this issue from happening. There are no known workarounds for this issue without upgrading. Embedders are recommended to upgrade and configure their embeddings as necessary to prevent possibly-malicious guests from triggering this issue.", "title": "osv - https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/GIT%2FCVE-2026-27204.json?alt=media" }, { "category": "description", "text": "No description is available for this CVE.", "title": "redhat - https://access.redhat.com/security/cve/CVE-2026-27204" }, { "category": "description", "text": "Wasmtime's implementation of WASI host interfaces are susceptible to guest-controlled resource exhaustion on the host. Wasmtime did not appropriately place limits on resource allocations requested by the guests. This serves as a Denial of Service vector where a guest can induce a range of crashing behaviors on the host such as:\n\n* Allocating arbitrarily large amounts of host memory.\n* Causing an allocation failure on the host, which in Rust defaults to aborting the process.\n* Causing a panic on the host due to over-large allocations being performed.\n* Cause degredation in performance of the host by holding excessive host memory alive.\n\nWasmtime's [security bug policy](https://docs.wasmtime.dev/security-what-is-considered-a-security-vulnerability.html) considers all of these behaviors a security vulnerability. Wasmtime's implementation of WASI has a number of different ways that resource exhaustion could happen, and fixing any one of them is insufficient from solving this vulnerability. A number of individual issues are grouped within this advisory and as a whole represent the known ways that guests can exhaust resources on the host.\n\nAn example of guest-controlled resource exhaustion within Wasmtime's implementation of WASI is guests could repeatedly allocate handles to themselves without limit. Some APIs also caused the host to perform a guest-controlled-sized allocation of a buffer on the host for I/O operations. Other APIs could force the host to buffer arbitrary amounts of data for the guest. Finally the guest could hand arbitrarily large allocations from itself to the host which could cause the host to perform an arbitrarily sized copy of memory which in some situations could result in quadratically sized allocations.\n\nWasmtime's implementations of WASIp1 and WASIp2 are affected by this vulnerability. Any host API modeled with the Component Model (or WIT) which operates on a `string` or `list` type is also affected. Not all WIT and WASI APIs are affected by this issue, but that's more of an exception so it's recommended for all embedders to consider themselves affected.\n\nTo address this issue a number of mitigations are being applied to limit the behavior of a guest in WASI. All of these mitigations manifest in the form of a limit of some kind applied to various situations, and as such all of these mitigations are backwards-incompatible as they run the risk of breaking preexisting programs. To address this all backports to previous stable releases have these limits tuned to overly-large values. This ensures that preexisting guests do not break while still providing embedders the knobs to prevent this DoS vector as well. The limits added to Wasmtime are:\n\n* `-Smax-resources=N` or `ResourceTable::set_max_capacity` - the maximum number of resources that a guest is allowed to allocate for itself.\n* `-Shostcall-fuel=N` or `Store::set_hostcall_fuel` - the maximum amount of data that the guest may copy to the host in a single function call.\n* `-Smax-random-size=N` or `WasiCtxBuilder::max_random_size` - the maximum size of the return value of `get-random-bytes` and `get-insecure-random-bytes` in the `wasi:random` implementations.\n* `-Smax-http-fields-size=N` or `WasiHttpCtx::set_max_fields_size` - the maximum size of headers for an HTTP request/response.\n\nThese settings are equally applicable to both WASIp1 and WASIp2. Wasmtime 41.0.x and prior previously did not limit these settings and the knobs being released are set to very large values by default to avoid any breaking behavior. Embedders will need to proactively tune these knobs as appropriate for their embeddings. The default settings in the unreleased Wasmtime 42.0.0 are 1M for max resources, 128MiB for hostcall fuel, 64MiB for max-random-size, and 32KiB for http fields size. Tuning is not expected for Wasmtime 42.0.0+.\n\nHosts/embedders affected by this issue are encouraged to audit and double-check their own host APIs they have implemented to see whether they are affected by this issue as well. The `-Shostcall-fuel` setting is intended to be a relatively coarse fix for many possible issues by limiting the amount of data for all host APIs at once, so many embedders may not need to take further action beyond updating Wasmtime and configuring it appropriately (if not updating to 42.0.0). Embedders should audit to see, however, if the guest is able to force the host to allocate on its behalf and ensure that the allocation is limited or tracked somehow.", "title": "gitlab - https://gitlab.com/api/v4/projects/25847700/repository/files/cargo%2Fwasmtime%2FCVE-2026-27204.yml/raw" }, { "category": "other", "text": "0.0007", "title": "EPSS" }, { "category": "other", "text": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "title": "CVSSV4" }, { "category": "other", "text": "6.9", "title": "CVSSV4 base score" }, { "category": "other", "text": "5.0", "title": "NCSC Score" }, { "category": "other", "text": "There is product data available from source Nvd, Is related to CWE-770 (Allocation of Resources Without Limits or Throttling)", "title": "NCSC Score top increasing factors" }, { "category": "other", "text": "Is related to (a version of) an uncommon product", "title": "NCSC Score top decreasing factors" }, { "category": "details", "text": "Severity: 2\n", "title": "Vendor assessment" } ], "product_status": { "fixed": [ "CSAFPID-5918964", "CSAFPID-5918968", "CSAFPID-5918969" ], "known_affected": [ "CSAFPID-5699782", "CSAFPID-5700061", "CSAFPID-5700062", "CSAFPID-5700063", "CSAFPID-5480178", "CSAFPID-5702047", "CSAFPID-5702048", "CSAFPID-5702049", "CSAFPID-2914823", "CSAFPID-5194593", "CSAFPID-3621837", "CSAFPID-3621838", "CSAFPID-3621839", "CSAFPID-3621840", "CSAFPID-3621841", "CSAFPID-3621842", "CSAFPID-3621843", "CSAFPID-3621844", "CSAFPID-3621845", "CSAFPID-3621846", "CSAFPID-3621847", "CSAFPID-3621848", "CSAFPID-3621849", "CSAFPID-3621850", "CSAFPID-3621851", "CSAFPID-3621852", "CSAFPID-3621853", "CSAFPID-3621854", "CSAFPID-3621855", "CSAFPID-3621856", "CSAFPID-3621857", "CSAFPID-3621858", "CSAFPID-3621859", "CSAFPID-3621860", "CSAFPID-3621861", "CSAFPID-3752405", "CSAFPID-3752406", "CSAFPID-3752407", "CSAFPID-3752408", "CSAFPID-5184645", "CSAFPID-5702046", "CSAFPID-5918970", "CSAFPID-5918971", "CSAFPID-5918972" ] }, "references": [ { "category": "external", "summary": "Source - github", "url": "https://github.com/advisories/GHSA-852m-cvvp-9p4w" }, { "category": "external", "summary": "Source raw - github", "url": "https://api.github.com/advisories/GHSA-852m-cvvp-9p4w" }, { "category": "external", "summary": "Source - nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27204" }, { "category": "external", "summary": "Source raw - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-27204" }, { "category": "external", "summary": "Source - cveprojectv5", "url": "https://www.cve.org/CVERecord?id=CVE-2026-27204" }, { "category": "external", "summary": "Source raw - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/27xxx/CVE-2026-27204.json" }, { "category": "external", "summary": "Source - debian", "url": "https://security-tracker.debian.org/tracker/CVE-2026-27204" }, { "category": "external", "summary": "Source - osv", "url": "https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/GIT%2FCVE-2026-27204.json?alt=media" }, { "category": "external", "summary": "Source - redhat", "url": "https://access.redhat.com/security/cve/CVE-2026-27204" }, { "category": "external", "summary": "Source raw - redhat", "url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-27204.json" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-27204" }, { "category": "external", "summary": "Source raw - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Source - gitlab", "url": "https://gitlab.com/api/v4/projects/25847700/repository/files/cargo%2Fwasmtime%2FCVE-2026-27204.yml/raw" }, { "category": "external", "summary": "Reference - cveprojectv5; github; gitlab; nvd; osv; redhat", "url": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-852m-cvvp-9p4w" }, { "category": "external", "summary": "Reference - cveprojectv5; github; gitlab; nvd; osv; redhat", "url": "https://github.com/bytecodealliance/wasmtime/issues/11552" }, { "category": "external", "summary": "Reference - cveprojectv5; github; gitlab; nvd; osv; redhat", "url": "https://github.com/bytecodealliance/wasmtime/pull/12599" }, { "category": "external", "summary": "Reference - cveprojectv5; github; gitlab; nvd; osv; redhat", "url": "https://docs.rs/wasmtime-wasi/latest/wasmtime_wasi/struct.WasiCtxBuilder.html#method.max_random_size" }, { "category": "external", "summary": "Reference - cveprojectv5; github; gitlab; nvd; osv; redhat", "url": "https://docs.rs/wasmtime/latest/wasmtime/component/struct.ResourceTable.html#method.set_max_capacity" }, { "category": "external", "summary": "Reference - cveprojectv5; github; gitlab; nvd; osv; redhat", "url": "https://docs.rs/wasmtime/latest/wasmtime/struct.Store.html#method.set_hostcall_fuel" }, { "category": "external", "summary": "Reference - cveprojectv5; github; gitlab; nvd; osv; redhat", "url": "https://docs.wasmtime.dev/security-what-is-considered-a-security-vulnerability.html" }, { "category": "external", "summary": "Reference - github; gitlab", "url": "https://github.com/advisories/GHSA-852m-cvvp-9p4w" }, { "category": "external", "summary": "Reference - osv", "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27204.json" }, { "category": "external", "summary": "Reference - github; gitlab; osv; redhat", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27204" }, { "category": "external", "summary": "Reference - redhat", "url": "https://www.cve.org/CVERecord?id=CVE-2026-27204" }, { "category": "external", "summary": "Reference - github; gitlab", "url": "https://rustsec.org/advisories/RUSTSEC-2026-0020.html" }, { "category": "external", "summary": "Reference - gitlab", "url": "https://github.com/bytecodealliance/wasmtime" } ], "remediations": [ { "category": "mitigation", "details": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.", "product_ids": [ "CSAFPID-2914823", "CSAFPID-5194593" ] } ], "scores": [ { "cvss_v3": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM" }, "products": [ "CSAFPID-2914823", "CSAFPID-3621837", "CSAFPID-3621838", "CSAFPID-3621839", "CSAFPID-3621840", "CSAFPID-3621841", "CSAFPID-3621842", "CSAFPID-3621843", "CSAFPID-3621844", "CSAFPID-3621845", "CSAFPID-3621846", "CSAFPID-3621847", "CSAFPID-3621848", "CSAFPID-3621849", "CSAFPID-3621850", "CSAFPID-3621851", "CSAFPID-3621852", "CSAFPID-3621853", "CSAFPID-3621854", "CSAFPID-3621855", "CSAFPID-3621856", "CSAFPID-3621857", "CSAFPID-3621858", "CSAFPID-3621859", "CSAFPID-3621860", "CSAFPID-3621861", "CSAFPID-3752405", "CSAFPID-3752406", "CSAFPID-3752407", "CSAFPID-3752408", "CSAFPID-5184645", "CSAFPID-5194593", "CSAFPID-5480178", "CSAFPID-5699782", "CSAFPID-5700061", "CSAFPID-5700062", "CSAFPID-5700063", "CSAFPID-5702046", "CSAFPID-5702047", "CSAFPID-5702048", "CSAFPID-5702049", "CSAFPID-5918970", "CSAFPID-5918971", "CSAFPID-5918972" ] } ], "title": "CVE-2026-27204" } ] }