CVE-2025-66506 (GCVE-0-2025-66506)

Vulnerability from cvelistv5 – Published: 2025-12-04 22:04 – Updated: 2025-12-05 15:32
VLAI
Title
Fulcio allocates excessive memory during token parsing
Summary
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.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-12-05 15:32 UTC
CWE
  • CWE-405 - Asymmetric Resource Consumption (Amplification)
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7639 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
sigstore fulcio Affected: < 1.8.3
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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