{"id":"CVE-2026-55149","summary":"Vouch Proxy: Unbounded Multipart Cookie Allocation DoS","details":"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.","aliases":["GHSA-qqff-5854-px68","GO-2026-6260"],"modified":"2026-09-18T03:30:52.104529815Z","published":"2026-09-15T16:30:37.580Z","related":["openSUSE-SU-2026:21761-1"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-789"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55149.json"},"references":[{"type":"WEB","url":"https://github.com/vouch/vouch-proxy/releases/tag/v0.48.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55149.json"},{"type":"ADVISORY","url":"https://github.com/vouch/vouch-proxy/security/advisories/GHSA-qqff-5854-px68"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55149"},{"type":"FIX","url":"https://github.com/vouch/vouch-proxy/commit/fa18ce30ba50a4863a436acad044c22965329c4f"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/vouch/vouch-proxy","events":[{"introduced":"0"},{"fixed":"fa18ce30ba50a4863a436acad044c22965329c4f"},{"fixed":"62eadec50dd1d8602a355edf2fc991b5e1e318d7"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"0.48.0"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v0.47.2","v0.47.1","v0.47.0","v0.45.1","v0.39.0","v0.37.3","v0.37.2","v0.37.1","v0.37.0","v0.36.0","v0.35.1","v0.35.0","v0.34.1","v0.34.0","v0.32.0","v0.31.1","v0.31.0","v0.30.0","v0.27.0","v0.23.1","v0.23.0","v0.20.0","v0.19.2","v0.19.1","v0.19.0","v0.17.3","v0.17.2","v0.17.1","v0.17.0","v0.16.4","v0.16.3","v0.16.2","v0.16.1","v0.16.0","v0.15.8","v0.15.7","v0.15.5","v0.15.4","v0.2.1","v0.2.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55149.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}