{ "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-2026-34202", "tracking": { "current_release_date": "2026-04-01T15:13:23.162665Z", "generator": { "date": "2026-02-17T15:00:00Z", "engine": { "name": "V.E.L.M.A", "version": "1.7" } }, "id": "CVE-2026-34202", "initial_release_date": "2026-03-28T07:40:41.176155Z", "revision_history": [ { "date": "2026-03-28T07:40:41.176155Z", "number": "1", "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (4).| CWES updated (1)." }, { "date": "2026-03-28T07:40:52.195340Z", "number": "2", "summary": "NCSC Score created." }, { "date": "2026-03-31T14:40:03.065179Z", "number": "3", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1).| Products created (1).| References created (3).| CWES updated (1)." }, { "date": "2026-03-31T14:40:05.982930Z", "number": "4", "summary": "NCSC Score updated." }, { "date": "2026-03-31T15:26:47.483936Z", "number": "5", "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)." }, { "date": "2026-03-31T15:26:50.111828Z", "number": "6", "summary": "NCSC Score updated." }, { "date": "2026-03-31T15:50:42.302261Z", "number": "7", "summary": "NCSC Score updated." }, { "date": "2026-03-31T17:38:52.625855Z", "number": "8", "summary": "Unknown change." }, { "date": "2026-03-31T19:55:24.286357Z", "number": "9", "summary": "References created (1)." }, { "date": "2026-04-01T15:13:06.005121Z", "number": "10", "summary": "Source connected.| CVE status created. (valid)| EPSS created." }, { "date": "2026-04-01T15:13:08.964560Z", "number": "11", "summary": "NCSC Score updated." } ], "status": "interim", "version": "11" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<4.3.0", "product": { "name": "vers:unknown/<4.3.0", "product_id": "CSAFPID-5968874" } } ], "category": "product_name", "name": "zebra" }, { "branches": [ { "category": "product_version_range", "name": "vers:unknown/<6.0.1", "product": { "name": "vers:unknown/<6.0.1", "product_id": "CSAFPID-5968878" } } ], "category": "product_name", "name": "zebra-chain" } ], "category": "vendor", "name": "ZcashFoundation" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-34202", "cwe": { "id": "CWE-1336", "name": "Improper Neutralization of Special Elements Used in a Template Engine" }, "notes": [ { "category": "description", "text": "---\n\n# Remote Denial of Service via Crafted V5 Transactions\n\n## Summary\nA vulnerability in Zebra's transaction processing logic allows a remote, unauthenticated attacker to cause a Zebra node to panic (crash). This is triggered by sending a specially crafted V5 transaction that passes initial deserialization but fails during transaction ID calculation.\n\n## Severity\n**Critical** - This is a Remote Denial of Service (DoS) that requires no authentication and can be triggered by a single network message.\n\n## Affected Versions\nAll Zebra versions supporting V5 transactions (Network Upgrade 5 and later) prior to **version 4.3.0**.\n\n## Description\nThe vulnerability stems from Zebra lazily validating transaction fields that are eagerly validated in the librustzcash parsing logic used when Zebra computes transaction ids and auth digests for V5 transactions where Zebra panics if those computations fail.\n\n`PushTransaction` messages with malformed V5 transactions are successfully deserialized as the zebra-chain `Transaction` type by the network codec, but when Zebra converts those transactions into internal types to compute the TxID expecting it to succeed, it triggers a panic/crash.\n\nAn attacker can trigger this crash by sending a single crafted `tx` message to a Zebra node's public P2P port. The same issue can be triggered via the `sendrawtransaction` RPC method.\n\n## Impact\n**Remote Denial of Service**\n* **Attack Vector:** Remote, unauthenticated.\n* **Effect:** Immediate crash of the Zebra node.\n* **Scope:** Any node with an open P2P port (default 8233) or exposed RPC interface is vulnerable.\n\n## Fixed Versions\nThis issue is fixed in **Zebra 4.3.0**. \n\nThe fix ensures that any transaction that would fail TxID calculation is rejected during the initial deserialization phase, and replaces internal panics with graceful error handling.\n\n## Mitigation\nUsers should upgrade to **Zebra 4.3.0** or later immediately. \n\nIf an immediate upgrade is not possible, users should ensure their RPC port is not exposed to the Internet. However, the P2P port must remain closed or restricted to trusted peers to fully mitigate the risk, which may impact the node's ability to sync with the network.\n\n## Credits\nZebra thanks [robustfengbin](https://github.com/robustfengbin), who discovered this issue and reported it via coordinated disclosure process.\n\n---", "title": "github - https://api.github.com/advisories/GHSA-qp6f-w4r3-h8wg" }, { "category": "description", "text": "ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.3.0 and zebra-chain version 6.0.1, a vulnerability in Zebra's transaction processing logic allows a remote, unauthenticated attacker to cause a Zebra node to panic (crash). This is triggered by sending a specially crafted V5 transaction that passes initial deserialization but fails during transaction ID calculation. This issue has been patched in zebrad version 4.3.0 and zebra-chain version 6.0.1.", "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34202.json" }, { "category": "description", "text": "ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.3.0 and zebra-chain version 6.0.1, a vulnerability in Zebra's transaction processing logic allows a remote, unauthenticated attacker to cause a Zebra node to panic (crash). This is triggered by sending a specially crafted V5 transaction that passes initial deserialization but fails during transaction ID calculation. This issue has been patched in zebrad version 4.3.0 and zebra-chain version 6.0.1.", "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-34202" }, { "category": "other", "text": "0.00187", "title": "EPSS" }, { "category": "other", "text": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H", "title": "CVSSV4" }, { "category": "other", "text": "9.2", "title": "CVSSV4 base score" }, { "category": "other", "text": "3.9", "title": "NCSC Score" }, { "category": "other", "text": "There is cwe data available from source Nvd, The value of the most recent EPSS score", "title": "NCSC Score top decreasing factors" } ], "product_status": { "known_affected": [ "CSAFPID-5968874", "CSAFPID-5968878" ] }, "references": [ { "category": "external", "summary": "Source - github", "url": "https://api.github.com/advisories/GHSA-qp6f-w4r3-h8wg" }, { "category": "external", "summary": "Source - cveprojectv5", "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/34xxx/CVE-2026-34202.json" }, { "category": "external", "summary": "Source - nvd", "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-34202" }, { "category": "external", "summary": "Source - first", "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nvd", "url": "https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-qp6f-w4r3-h8wg" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nvd", "url": "https://github.com/ZcashFoundation/zebra/releases/tag/v4.3.0" }, { "category": "external", "summary": "Reference - cveprojectv5; github; nvd", "url": "https://zfnd.org/zebra-4-3-0-critical-security-fixes-zip-235-support-and-performance-improvements" }, { "category": "external", "summary": "Reference - github", "url": "https://github.com/advisories/GHSA-qp6f-w4r3-h8wg" }, { "category": "external", "summary": "Reference - github", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34202" } ], "title": "CVE-2026-34202" } ] }