{"id":"CVE-2026-49478","aliases":["GHSA-f5mr-q85p-6hh6","GO-2026-5853"],"url":"https://o3.security/vulnerability/CVE-2026-49478","summary":"Fulcio has OIDC Discovery Redirect Following Allows SSRF and JWKS Substitution for Meta-Issuer Paths, with Kubernetes Service-Account Token Leakage","details":"Fulcio is a certificate authority for issuing code signing certificates for an OpenID Connect (OIDC) identity. Versions through 1.8.5 improperly follow cross-host redirects and attach Kubernetes ServiceAccount tokens during OIDC discovery, allowing a malicious or compromised issuer to perform blind SSRF, substitute and cache malicious JWKS keys, or disclose ServiceAccount tokens to external hosts. Version 1.8.6 blocks cross-host redirects, restricts token injection, and restricts local token loading. No known workarounds are available.","published":"2026-08-13T13:08:21.498Z","modified":"2026-09-11T03:48:26.313724351Z","cvss":{"score":8.7,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N"},"epss":{"score":0.00175,"percentile":0.07174,"asOf":"2026-09-15"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/sigstore/fulcio","fixedVersion":"1.8.6"}],"fix":{"url":"https://github.com/sigstore/fulcio/commit/378c654f48c3bafdced04ead7010aab2cb4c6ca1","label":"sigstore/fulcio@378c654"},"references":[{"type":"WEB","url":"https://github.com/sigstore/fulcio/releases/tag/v1.8.6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49478.json"},{"type":"ADVISORY","url":"https://github.com/sigstore/fulcio/security/advisories/GHSA-f5mr-q85p-6hh6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49478"},{"type":"FIX","url":"https://github.com/sigstore/fulcio/commit/378c654f48c3bafdced04ead7010aab2cb4c6ca1"},{"type":"FIX","url":"https://github.com/sigstore/fulcio/pull/2354"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-11T03:48:26.313724351Z"}}