CVE-2025-66564
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk37th percentile - higher than 37% of all known CVEs
Summary
Sigstore Timestamp Authority is a service for issuing RFC 3161 timestamps. Prior to 2.0.3, the functions api.ParseJSONRequest and api.getContentType split untrusted data (an optional OID or the Content-Type header) on period or application strings, causing O(n)-byte allocations when handling a malicious request with an excessively long OID or malformed Content-Type header. This vulnerability is fixed in 2.0.3.
Risk Assessment
An attacker could send a specially crafted request, causing excessive memory consumption and potential denial of service (DoS) in the Timestamp Authority service. This may disrupt timestamp issuance for signatures and code signing processes.
Recommendation
Upgrade Sigstore Timestamp Authority to version 2.0.3 or later.
Other vulnerabilities in Sigstore Timestamp Authority
See all- CVE-2026-39984Medium
Sigstore Timestamp Authority is a service for issuing RFC 3161 timestamps. Versions 2.0.5 and below contain an authorization bypass vulnerability in the VerifyTimestampResponse function.
- CVE-2026-49835Medium
A vulnerability in Sigstore Timestamp Authority before version 2.1.0 allows an unauthenticated remote attacker to send requests with random paths or HTTP methods, causing unbounded permanent time-series entries in Prometheus metrics and leading to memory exhaustion.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS