VULNERABILITY INTELLIGENCE

CVE-2025-66506

CVSS score7.5 HIGH
EPSS probability0.21%
CISA KEVNot currently listed
Published2025-12-04
Last modified2026-10-18
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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

Weakness classification

  • security-advisories@github.com: CWE-405

Primary references