Sigstore Timestamp Authority has Improper Certificate Validation in verifier (sigstore timestamp-authority)
En bref
- Source
- NVD
- EPSS
- EPSS 0.10 % · centile 1 ()
- État
- PUBLISHED
- Publiée
- Mise à jour
- Attribuée par
- GitHub_M
- Statut NVD
- Analyzed
Description
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. VerifyTimestampResponse correctly verifies the certificate chain signature, but the TSA-specific constraint checks in VerifyLeafCert uses the first non-CA certificate from the PKCS#7 certificate bag instead of the leaf certificate from the verified chain. An attacker can exploit this by prepending a forged certificate to the certificate bag while the message is signed with an authorized key, causing the library to validate the signature against one certificate but perform authorization checks against another. This vulnerability only affects users of the timestamp-authority/v2/pkg/verification package and does not affect the timestamp-authority service itself or sigstore-go. The issue has been fixed in version 2.0.6.
Faiblesses (CWE)
- CWE-295 — Validation incorrecte de certificat
Références
Scores
| Version | Score | Vecteur | Évalué par |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N | GitHub_M |
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N | NVD · security-advisories@github.com (Secondary) |
Avis
- GHSA-xm5m-wgh2-rrg3 — Sigstore Timestamp Authority has Improper Certificate Validation in verifier
- GO-2026-5763 — Sigstore Timestamp Authority has Improper Certificate Validation in verifier in github.com/sigstore/timestamp-authority
Références européennes
- ENISA EUVD · EUVD-2026-22813
- GCVE · GCVE-0-2026-39984
Avis du CERT-FR
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
Configurations affectées (CPE NVD)
cpe:2.3:a:linuxfoundation:sigstore_timestamp_authority:*:*:*:*:*:*:*:*< 2.0.6
Produits affectés
| Produit | Versions |
|---|---|
| sigstore · timestamp-authority | affected < 2.0.6 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |