Cosign provides code signing and transparency for containers and binaries. In versions 3.0.4 and below, an issuing certificate with a validity that expires before the leaf certificate will be considered valid during verification even if the provided timestamp would mean the issuing certificate should be considered expired. When verifying artifact signatures using a certificate, Cosign first verifies the certificate chain using the leaf certificate's "not before" timestamp and later checks expiry of the leaf certificate using either a signed timestamp provided by the Rekor transparency log or from a timestamp authority, or using the current time. The root and all issuing certificates are assumed to be valid during the leaf certificate's validity. There is no impact to users of the public Sigstore infrastructure. This may affect private deployments with customized PKIs. This issue has been fixed in version 3.0.5.
Metrics
Affected Vendors & Products
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-wfqv-66vq-46rm | Cosign considered signatures valid with expired intermediate certificates when transparency log verification is skipped |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 20 Feb 2026 10:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Sigstore
Sigstore cosign |
|
| Vendors & Products |
Sigstore
Sigstore cosign |
Thu, 19 Feb 2026 22:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Cosign provides code signing and transparency for containers and binaries. In versions 3.0.4 and below, an issuing certificate with a validity that expires before the leaf certificate will be considered valid during verification even if the provided timestamp would mean the issuing certificate should be considered expired. When verifying artifact signatures using a certificate, Cosign first verifies the certificate chain using the leaf certificate's "not before" timestamp and later checks expiry of the leaf certificate using either a signed timestamp provided by the Rekor transparency log or from a timestamp authority, or using the current time. The root and all issuing certificates are assumed to be valid during the leaf certificate's validity. There is no impact to users of the public Sigstore infrastructure. This may affect private deployments with customized PKIs. This issue has been fixed in version 3.0.5. | |
| Title | Cosign Certificate Chain Expiry Validation Issue Allows Issuing Certificate Expiry to Be Overlooked | |
| Weaknesses | CWE-295 | |
| References |
| |
| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-02-19T22:27:08.828Z
Reserved: 2026-01-21T18:38:22.473Z
Link: CVE-2026-24122
No data.
Status : Received
Published: 2026-02-19T23:16:24.517
Modified: 2026-02-19T23:16:24.517
Link: CVE-2026-24122
No data.
OpenCVE Enrichment
Updated: 2026-02-20T09:53:45Z
Weaknesses
Github GHSA