CVE-2025-66506

Fulcio is a free-to-use certificate authority for issuing code signing certificates for an OpenID Connect (OIDC) identity. Prior to 1.8.3, function identity.extractIssuerURL splits (via a call to strings.Split) its argument (which is untrusted data) on periods. As a result, in the face of a malicious request with an (invalid) OIDC identity token in the payload containing many period characters, a call to extractIssuerURL incurs allocations to the tune of O(n) bytes (where n stands for the length of the function's argument), with a constant factor of about 16. This vulnerability is fixed in 1.8.3.

The following products are affected by CVE-2025-66506 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2025-66506.

URL	Resource
https://github.com/sigstore/fulcio/commit/765a0e57608b9ef390e1eeeea8595b9054c63a5a
https://github.com/sigstore/fulcio/security/advisories/GHSA-f83f-xpx7-ffpw
https://nvd.nist.gov/vuln/detail/CVE-2025-66506
https://www.cve.org/CVERecord?id=CVE-2025-66506