{"id":"CVE-2026-35030","aliases":["GHSA-jjhc-v7c2-5hh6","PYSEC-2026-390"],"url":"https://o3.security/vulnerability/CVE-2026-35030","summary":"LiteLLM has an authentication bypass via OIDC userinfo cache key collision","details":"###  Impact\n\nWhen JWT authentication is enabled (`enable_jwt_auth: true`), the OIDC userinfo cache uses `token[:20]` as the cache key. JWT headers produced by the same signing algorithm generate identical first 20 characters.\n\nThis configuration option is not enabled by default. **Most instances are not affected.**\n\nAn unauthenticated attacker can craft a token whose first 20 characters match a legitimate user's cached token. On cache hit, the attacker inherits the legitimate user's identity and permissions. This affects deployments with JWT/OIDC authentication enabled.\n\n###  Patches\n\nFixed in v1.83.0. The cache key now uses the full hash of the JWT token.\n\n###  Workarounds\n\nDisable OIDC userinfo caching by setting the cache TTL to 0, or disable JWT authentication entirely.","published":"2026-04-06T16:47:02.065Z","modified":"2026-08-12T03:51:47.991601544Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"litellm","fixedVersion":"1.83.0"}],"fix":null,"references":[{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-35030.json"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:13545"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:28960"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:30056"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-35030"},{"type":"ADVISORY","url":"https://github.com/BerriAI/litellm/security/advisories/GHSA-jjhc-v7c2-5hh6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35030.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-35030"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2455509"},{"type":"PACKAGE","url":"https://github.com/BerriAI/litellm"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:47.991601544Z"}}