Fulcio allocates excessive memory during token parsing
Summary
Fulcio allocates excessive memory during token parsing
Original description
The description as published by the source.
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.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2025-66506 golang-github-sigstore-fulcio
- Ubuntu UBUNTU-CVE-2025-66506 golang-github-sigstore-fulcio
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- patch github.com