Vulnerability in Linuxfoundation Sigstore Timestamp Authority
CVE-2025-66564
Sigstore Timestamp Authority is a service for issuing RFC 3161 timestamps. Prior to 2.0.3, Function api.ParseJSONRequest currently splits (via a call to strings.Split) an optionally-provided OID (which is untrusted data) on periods. Similarly, function api.getContentType splits the Content-Type header (which is also untrusted data) on an application string. As a result, in the face of a malicious request with either an excessively long OID in the payload containing many period characters or a malformed Content-Type header, a call to api.ParseJSONRequest or api.getContentType incurs allocations of O(n) bytes (where n stands for the length of the function's argument). This vulnerability is fixed in 2.0.3.
EPSS: 0.004 (37.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Linuxfoundation Sigstore_timestamp_authority
- Sigstore Timestamp-authority — versions < 2.0.3
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-66564?
- CVE-2025-66564 is a high-severity vulnerability in Linuxfoundation Sigstore Timestamp Authority, classified under Asymmetric Resource Consumption (Amplification). CVSS score: 7.5/10. Published 2025-12-04.
- How severe is CVE-2025-66564?
- High severity. CVSS v3 base score is 7.5 out of 10.