{ "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-2026-2836", "tracking": { "current_release_date": "2026-03-20T09:37:47.215474Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-2836", "initial_release_date": "2026-03-05T00:25:01.619982Z", "revision_history": [ { "date": "2026-03-05T00:25:01.619982Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (1)." }, { "date": "2026-03-05T00:25:05.915379Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-03-05T00:38:32.758801Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1).| References created (1)." }, { "date": "2026-03-05T00:38:36.238678Z", "number": "4", "summary": "NCSC Score updated." }, { "date": "2026-03-05T14:13:07.224939Z", "number": "5", "summary": "Source created.| CVE status created. (valid)| EPSS created." }, { "date": "2026-03-05T14:13:10.166914Z", "number": "6", "summary": "NCSC Score updated." }, { "date": "2026-03-05T21:40:04.746673Z", "number": "7", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (4).| CWES updated (1)." }, { "date": "2026-03-05T21:40:07.622761Z", "number": "8", "summary": "NCSC Score updated." }, { "date": "2026-03-06T19:25:01.768717Z", "number": "9", "summary": "CWES updated (1)." }, { "date": "2026-03-06T19:25:09.774786Z", "number": "10", "summary": "NCSC Score updated." }, { "date": "2026-03-06T19:38:50.859990Z", "number": "11", "summary": "CWES updated (1).| Unknown change." }, { "date": "2026-03-06T19:38:54.185838Z", "number": "12", "summary": "NCSC Score updated." }, { "date": "2026-03-09T21:47:12.952418Z", "number": "13", "summary": "Description removed for source.| Description created for source." }, { "date": "2026-03-09T21:47:21.237732Z", "number": "14", "summary": "NCSC Score updated." }, { "date": "2026-03-12T15:25:35.127356Z", "number": "15", "summary": "CVSS created.| Products connected (1).| Product Identifiers created (1)." }, { "date": "2026-03-12T15:25:44.322673Z", "number": "16", "summary": "NCSC Score updated." }, { "date": "2026-03-20T09:37:42.948825Z", "number": "17", "summary": "Source connected.| CVE status created. (valid)| EPSS created." }, { "date": "2026-03-20T09:37:46.653994Z", "number": "18", "summary": "NCSC Score updated." } ], "status": "interim", "version": "18" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:semver/<0.8.0", "product": { "name": "vers:semver/<0.8.0", "product_id": "CSAFPID-5759431" } } ], "category": "product_name", "name": "https://github.com/cloudflare/pingora" }, { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<0.8.0", "product": { "name": "vers:unknown/<0.8.0", "product_id": "CSAFPID-5810444", "product_identification_helper": { "cpe": "cpe:2.3:a:cloudflare:pingora:*:*:*:*:*:*:*:*" } } } ], "category": "product_name", "name": "pingora" } ], "category": "vendor", "name": "Cloudflare" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-2836", "cwe": { "id": "CWE-639", "name": "Authorization Bypass Through User-Controlled Key" }, "notes": [ { "category": "description", "text": "A cache poisoning vulnerability has been found in the Pingora HTTP proxy framework’s default cache key construction. The issue occurs because the default HTTP cache key implementation generates cache keys using only the URI path, excluding critical factors such as the host header (authority). Operators relying on the default are vulnerable to cache poisoning, and cross-origin responses may be improperly served to users.\n\n\nImpact\n\nThis vulnerability affects users of Pingora's alpha proxy caching feature who relied on the default CacheKey implementation. An attacker could exploit this for:\n\n * Cross-tenant data leakage: In multi-tenant deployments, poison the cache so that users from one tenant receive cached responses from another tenant\n\n\n * Cache poisoning attacks: Serve malicious content to legitimate users by poisoning shared cache entries\n\n\n\n\nCloudflare's CDN infrastructure was not affected by this vulnerability, as Cloudflare's default cache key implementation uses multiple factors to prevent cache key poisoning and never made use of the previously provided default.\n\n\nMitigation:\n\nWe strongly recommend Pingora users to upgrade to Pingora v0.8.0 or higher, which removes the insecure default cache key implementation. Users must now explicitly implement their own callback that includes appropriate factors such as Host header, origin server HTTP scheme, and other attributes their cache should vary on.\n\n\nPingora users on previous versions may also remove any of their default CacheKey usage and implement their own that should at minimum include the host header / authority and upstream peer’s HTTP scheme.", "title": "nvd - https://nvd.nist.gov/vuln/detail/CVE-2026-2836" }, { "category": "description", "text": "A cache poisoning vulnerability has been found in the Pingora HTTP proxy framework’s default cache key construction. The issue occurs because the default HTTP cache key implementation generates cache keys using only the URI path, excluding critical factors such as the host header (authority). Operators relying on the default are vulnerable to cache poisoning, and cross-origin responses may be improperly served to users.\n\n\nImpact\n\nThis vulnerability affects users of Pingora's alpha proxy caching feature who relied on the default CacheKey implementation. An attacker could exploit this for:\n\n * Cross-tenant data leakage: In multi-tenant deployments, poison the cache so that users from one tenant receive cached responses from another tenant\n\n\n * Cache poisoning attacks: Serve malicious content to legitimate users by poisoning shared cache entries\n\n\n\n\nCloudflare's CDN infrastructure was not affected by this vulnerability, as Cloudflare's default cache key implementation uses multiple factors to prevent cache key poisoning and never made use of the previously provided default.\n\n\nMitigation:\n\nWe strongly recommend Pingora users to upgrade to Pingora v0.8.0 or higher, which removes the insecure default cache key implementation. Users must now explicitly implement their own callback that includes appropriate factors such as Host header, origin server HTTP scheme, and other attributes their cache should vary on.\n\n\nPingora users on previous versions may also remove any of their default CacheKey usage and implement their own that should at minimum include the host header / authority and upstream peer’s HTTP scheme.", "title": "cveprojectv5 - https://www.cve.org/CVERecord?id=CVE-2026-2836" }, { "category": "description", "text": "### Impact\nPingora versions prior to 0.8.0 generated cache keys using only the URI path, excluding critical factors such as the host header. This allows an attacker to poison the cache and serve cross-origin responses to users.\n\nThis vulnerability affects users of Pingora's alpha proxy caching feature who relied on the default CacheKey implementation. An attacker could exploit this for cross-tenant data leakage in multi-tenant deployments, or serve malicious content to legitimate users by poisoning shared cache entries.\n\nNote: Cloudflare customers and Cloudflare's CDN infrastructure were not affected by this vulnerability, as Cloudflare's default cache key implementation uses multiple factors to prevent cache key poisoning and never made use of the previously provided default.\n\n### Patches\nWe strongly suggest users should upgrade to Pingora v.0.8.0 or higher, which removes the default CacheKey implementation.\n\n### Workarounds\nDo not rely on the provided CacheKey default, and at minimum use the host / :authority and the upstream peer TLS scheme as part of building the CacheKey, as well as other factors that may apply to the deployment e.g. HTTP method. \n\n### References\nSee [CVE-2026-2836](https://cve.org/CVERecord?id=CVE-2026-2836) and the [Cloudflare blog post](https://blog.cloudflare.com/pingora-oss-smuggling-vulnerabilities/) for more details.\n\n### Credits\nDisclosed responsibly by Rajat Raghav (@xclow3n) through the Cloudflare [Bug Bounty Program](https://www.cloudflare.com/disclosure/).", "title": "github - https://github.com/advisories/GHSA-f93w-pcj3-rggc" }, { "category": "other", "text": "6e-05", "title": "EPSS" }, { "category": "other", "text": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N/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": "8.4", "title": "CVSSV4 base score" }, { "category": "other", "text": "4.4", "title": "NCSC Score" }, { "category": "other", "text": "Is related to CWE-639 (Authorization Bypass Through User-Controlled Key)", "title": "NCSC Score top decreasing factors" } ], "product_status": { "known_affected": [ "CSAFPID-5759431", "CSAFPID-5810444" ] }, "references": [ { "category": "external", "summary": "Source - nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-2836" }, { "category": "external", "summary": "Source raw - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-2836" }, { "category": "external", "summary": "Source - cveprojectv5", "url": "https://www.cve.org/CVERecord?id=CVE-2026-2836" }, { "category": "external", "summary": "Source raw - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/2xxx/CVE-2026-2836.json" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-2836" }, { "category": "external", "summary": "Source raw - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Source - github", "url": "https://github.com/advisories/GHSA-f93w-pcj3-rggc" }, { "category": "external", "summary": "Source raw - github", "url": "https://api.github.com/advisories/GHSA-f93w-pcj3-rggc" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Reference - cveprojectv5; nvd", "url": "https://github.com/cloudflare/pingora" }, { "category": "external", "summary": "Reference - github", "url": "https://github.com/cloudflare/pingora/security/advisories/GHSA-f93w-pcj3-rggc" }, { "category": "external", "summary": "Reference - github", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-2836" }, { "category": "external", "summary": "Reference - github", "url": "https://rustsec.org/advisories/RUSTSEC-2026-0035.html" }, { "category": "external", "summary": "Reference - github", "url": "https://github.com/advisories/GHSA-f93w-pcj3-rggc" } ], "scores": [ { "cvss_v3": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N", "baseScore": 8.1, "baseSeverity": "HIGH" }, "products": [ "CSAFPID-5759431", "CSAFPID-5810444" ] } ], "title": "CVE-2026-2836" } ] }