Cosign verification accepts any valid Rekor entry under certain conditions (sigstore cosign)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.11 % · percentile 1 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
Cosign provides code signing and transparency for containers and binaries. Prior to versions 2.6.2 and 3.0.4, Cosign bundle can be crafted to successfully verify an artifact even if the embedded Rekor entry does not reference the artifact's digest, signature or public key. When verifying a Rekor entry, Cosign verifies the Rekor entry signature, and also compares the artifact's digest, the user's public key from either a Fulcio certificate or provided by the user, and the artifact signature to the Rekor entry contents. Without these comparisons, Cosign would accept any response from Rekor as valid. A malicious actor that has compromised a user's identity or signing key could construct a valid Cosign bundle by including any arbitrary Rekor entry, thus preventing the user from being able to audit the signing event. This issue has been patched in versions 2.6.2 and 3.0.4.
Weaknesses (CWE)
- CWE-345 — Insufficient Verification of Data Authenticity
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N | GitHub_M |
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N | NVD · nvd@nist.gov (Primary) |
Advisories
- GHSA-whqx-f9j3-ch6m — Cosign verification accepts any valid Rekor entry under certain conditions
- GO-2026-4309 — Cosign verification accepts any valid Rekor entry under certain conditions in github.com/sigstore/cosign
European references
- ENISA EUVD · EUVD-2026-1868
- GCVE · GCVE-0-2026-22703
CERT-FR advisories
- CERTFR-2026-AVI-0315 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0209 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0199 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:sigstore:cosign:*:*:*:*:*:*:*:*< 2.6.2cpe:2.3:a:sigstore:cosign:*:*:*:*:*:*:*:*≥ 3.0.0 < 3.0.4
Affected products
| Product | Versions |
|---|---|
| sigstore · cosign | affected < 3.0.4 ; affected < 2.6.2 |
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 |