{"id":"CVE-2026-55149","title":"Vouch Proxy is an SSO and OAuth/OIDC login solution for Nginx using the auth_request module","summary":"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 val…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-789"],"vendor":"vouch","product":"vouch-proxy","affected":["vouch-proxy < 0.48.0"],"patched":["github.com/vouch/vouch-proxy 0.48.0"],"published":"2026-09-15","updated":"2026-09-17","sourceUpdated":"2026-09-17T17:16:44.293","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55149","references":[{"url":"https://github.com/vouch/vouch-proxy/commit/fa18ce30ba50a4863a436acad044c22965329c4f","label":"security-advisories@github.com"},{"url":"https://github.com/vouch/vouch-proxy/releases/tag/v0.48.0","label":"security-advisories@github.com"},{"url":"https://github.com/vouch/vouch-proxy/security/advisories/GHSA-qqff-5854-px68","label":"security-advisories@github.com"},{"url":"https://github.com/vouch/vouch-proxy/security/advisories/GHSA-qqff-5854-px68","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://github.com/advisories/GHSA-qqff-5854-px68"}],"tags":["nvd","cve.org","exploit-available","ghsa","go"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-17T16:05:30.568513Z"},"epss":0.00399,"epssPercentile":0.33814,"aliases":["GHSA-qqff-5854-px68"],"ecosystem":"go","ingestedAt":"2026-08-20T17:59:05.945Z","slug":"CVE-2026-55149","body":"## Overview\n\nVouch 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-55149)\n\nAffected packages:\n\n- `github.com/vouch/vouch-proxy <= 0.47.2`\n\nPatched in:\n\n- `github.com/vouch/vouch-proxy 0.48.0`\n\nSource: https://github.com/advisories/GHSA-qqff-5854-px68","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":206293,"id":"CVE-2026-55149","ts":1789662193093,"field":"exploit_available","old":"false","new":"true"}]}