Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Sigstore | Cosign | < 2.6.2 |
Related Weaknesses (CWE)
References
- https://github.com/sigstore/cosign/commit/6832fba4928c1ad69400235bbc41212de50061Patch
- https://github.com/sigstore/cosign/pull/4623Issue Tracking
- https://github.com/sigstore/cosign/security/advisories/GHSA-whqx-f9j3-ch6mExploitVendor Advisory
FAQ
What is CVE-2026-22703?
CVE-2026-22703 is a vulnerability with a CVSS score of 5.5 (MEDIUM). 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...
How severe is CVE-2026-22703?
CVE-2026-22703 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-22703?
Check the references section above for vendor advisories and patch information. Affected products include: Sigstore Cosign.