{"id":"CVE-2026-55149","sourceIdentifier":"security-advisories@github.com","published":"2026-09-15T17:17:21.893","lastModified":"2026-09-30T17:51:56.193","vulnStatus":"Deferred","cveTags":[],"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":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"vouch","product":"vouch-proxy","versions":[{"version":"< 0.48.0","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-17T16:05:30.568513Z","id":"CVE-2026-55149","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-789"}]}],"references":[{"url":"https://github.com/vouch/vouch-proxy/commit/fa18ce30ba50a4863a436acad044c22965329c4f","source":"security-advisories@github.com"},{"url":"https://github.com/vouch/vouch-proxy/releases/tag/v0.48.0","source":"security-advisories@github.com"},{"url":"https://github.com/vouch/vouch-proxy/security/advisories/GHSA-qqff-5854-px68","source":"security-advisories@github.com"},{"url":"https://github.com/vouch/vouch-proxy/security/advisories/GHSA-qqff-5854-px68","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}