{"id":"CVE-2025-66564","aliases":["GHSA-4qg8-fj49-pxjh","GO-2025-4192"],"url":"https://o3.security/vulnerability/CVE-2025-66564","summary":"Sigstore Timestamp Authority allocates excessive memory during request parsing","details":"### Impact\n\n**Excessive memory allocation**\n\nFunction [api.ParseJSONRequest](https://github.com/sigstore/timestamp-authority/blob/26d7d426d3000abdbdf2df34de56bb92246c0365/pkg/api/timestamp.go#L63) currently splits (via a call to [strings.Split](https://pkg.go.dev/strings#Split)) an optionally-provided OID (which is untrusted data) on periods. Similarly, function [api.getContentType](https://github.com/sigstore/timestamp-authority/blob/26d7d426d3000abdbdf2df34de56bb92246c0365/pkg/api/timestamp.go#L114) splits the `Content-Type` header (which is also untrusted data) on an `application` string.\n\nAs 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). Relevant weakness: [CWE-405: Asymmetric Resource Consumption (Amplification)](https://cwe.mitre.org/data/definitions/405.html)\n\n### Patches\n\nUpgrade to v2.0.3.\n\n### Workarounds\n\nThere are no workarounds with the service itself. If the service is behind a load balancer, configure the load balancer to reject excessively large requests.","published":"2025-12-04T22:37:13.307Z","modified":"2026-08-12T03:51:13.995849552Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/sigstore/timestamp-authority","fixedVersion":"2.0.3"}],"fix":{"url":"https://github.com/sigstore/timestamp-authority/commit/0cae34e197d685a14904e0bad135b89d13b69421","label":"sigstore/timestamp-authority@0cae34e"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66564.json"},{"type":"ADVISORY","url":"https://github.com/sigstore/timestamp-authority/security/advisories/GHSA-4qg8-fj49-pxjh"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-66564"},{"type":"FIX","url":"https://github.com/sigstore/timestamp-authority/commit/0cae34e197d685a14904e0bad135b89d13b69421"},{"type":"PACKAGE","url":"https://github.com/sigstore/timestamp-authority"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:13.995849552Z"}}