Advisories for Golang/Github.com/Sigstore/Timestamp-Authority/V2 package

2026

Sigstore Timestamp Authority has OOM due to unbounded metric label cardinality

An unauthenticated remote attacker can trigger unbounded memory growth on the timestamp authority server. This vulnerability exists because the global wrapMetrics middleware records the raw HTTP request path (r.URL.Path) and raw HTTP request method (r.Method) as Prometheus labels for latency and request count metric vectors. Since this middleware runs before standard routing occurs, it executes for all incoming requests, including those for unmatched paths (yielding 404 responses) or arbitrary request …

Sigstore Timestamp Authority has Improper Certificate Validation in verifier

Authorization bypass via certificate bag manipulation in sigstore/timestamp-authority verifier An authorization bypass vulnerability exists in sigstore/timestamp-authority verifier (timestamp-authority/v2/pkg/verification): VerifyTimestampResponse function correctly verifies the certificate chain but when the TSA specific constraints are verified in VerifyLeafCert, the first non-CA certificate from the PKCS#7 certificate bag is used instead of the leaf certificate from the certificate chain. An attacker can exploit this by prepending a forged certificate to the certificate bag while …