CVE-2025-66506

Publication date

2025-12-04 22:04:41

Family

GitHub_M

State

PUBLISHED

Description

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 functions argument), with a constant factor of about 16. This vulnerability is fixed in 1.8.3.