CVE-2026-49478

high

Description

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.

References

https://github.com/sigstore/fulcio/security/advisories/GHSA-f5mr-q85p-6hh6

https://github.com/sigstore/fulcio/releases/tag/v1.8.6

https://github.com/sigstore/fulcio/pull/2354

https://github.com/sigstore/fulcio/commit/378c654f48c3bafdced04ead7010aab2cb4c6ca1

Details

Source: Mitre, NVD

Published: 2026-08-13

Updated: 2026-08-15

Risk Information

CVSS v2

Base Score: 7.1

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 8.7

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N

Severity: High

EPSS

EPSS: 0.00282