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.
Exploitability
AV:NAC:HPR:NUI:NScope
S:CImpact
C:HI:HA:N8.7/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:NInput Validation