{"id":"CVE-2026-55149","state":"PUBLISHED","title":"Vouch Proxy: Unbounded Multipart Cookie Allocation DoS","description":"Vouch Proxy is an SSO and OAuth/OIDC login solution for Nginx using the auth_request module. Prior to 0.48.0, Cookie in pkg/cookie/cookie.go parses the total part count from an attacker-controlled multipart cookie name and passes the value to make([]string, numParts) without checking that the value is positive or reasonably bounded. Requests to /validate and /_external-auth-:id reach JWTCacheHandler in pkg/jwtmanager/jwtcache.go, FindJWT in pkg/jwtmanager/jwtmanager.go, and the vulnerable cookie reassembly before JWT validation, so no account or valid session is required. A cookie name such as VouchCookie_1of10000000000 causes an attempted slice allocation of roughly 160 GB and a fatal Go runtime out-of-memory condition, allowing one request to crash the authentication proxy and repeated requests to sustain unavailability. This vulnerability is fixed in 0.48.0.","publishedAt":"2026-09-15T16:30:37.580Z","updatedAt":"2026-09-17T16:08:18.413Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["vouch vouch-proxy"],"affected":[{"vendor":"vouch","product":"vouch-proxy","versions":[{"version":"< 0.48.0","status":"affected"}]}],"references":["https://github.com/vouch/vouch-proxy/security/advisories/GHSA-qqff-5854-px68","https://github.com/vouch/vouch-proxy/commit/fa18ce30ba50a4863a436acad044c22965329c4f","https://github.com/vouch/vouch-proxy/releases/tag/v0.48.0"],"weaknesses":["CWE-789"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55149.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55149","state":"PUBLISHED","datePublished":"2026-09-15T16:30:37.580Z","dateUpdated":"2026-09-17T16:08:18.413Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-16T15:13:28.164Z"},"containers":{"cna":{"title":"Vouch Proxy: Unbounded Multipart Cookie Allocation DoS","descriptions":[{"lang":"en","value":"Vouch Proxy is an SSO and OAuth/OIDC login solution for Nginx using the auth_request module. Prior to 0.48.0, Cookie in pkg/cookie/cookie.go parses the total part count from an attacker-controlled multipart cookie name and passes the value to make([]string, numParts) without checking that the value is positive or reasonably bounded. Requests to /validate and /_external-auth-:id reach JWTCacheHandler in pkg/jwtmanager/jwtcache.go, FindJWT in pkg/jwtmanager/jwtmanager.go, and the vulnerable cookie reassembly before JWT validation, so no account or valid session is required. A cookie name such as VouchCookie_1of10000000000 causes an attempted slice allocation of roughly 160 GB and a fatal Go runtime out-of-memory condition, allowing one request to crash the authentication proxy and repeated requests to sustain unavailability. This vulnerability is fixed in 0.48.0."}],"affected":[{"vendor":"vouch","product":"vouch-proxy","versions":[{"version":"< 0.48.0","status":"affected"}]}],"references":[{"url":"https://github.com/vouch/vouch-proxy/security/advisories/GHSA-qqff-5854-px68","name":"https://github.com/vouch/vouch-proxy/security/advisories/GHSA-qqff-5854-px68","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/vouch/vouch-proxy/commit/fa18ce30ba50a4863a436acad044c22965329c4f","name":"https://github.com/vouch/vouch-proxy/commit/fa18ce30ba50a4863a436acad044c22965329c4f","tags":["x_refsource_MISC"]},{"url":"https://github.com/vouch/vouch-proxy/releases/tag/v0.48.0","name":"https://github.com/vouch/vouch-proxy/releases/tag/v0.48.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-789","lang":"en","description":"CWE-789: Memory Allocation with Excessive Size Value","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-15T16:30:37.580Z"},"source":{"advisory":"GHSA-qqff-5854-px68","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/vouch/vouch-proxy/security/advisories/GHSA-qqff-5854-px68","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-17T16:05:30.568513Z","id":"CVE-2026-55149","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-17T16:08:18.413Z"}}]}}}