CVE-2026-39395: Cosign's verify-blob-attestation reports false positive when payload parsing fails
sigstore · cosign
Affected: sigstore cosign · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 16% of scored CVEs
DescriptionCVE.org
Cosign provides code signing and transparency for containers and binaries. Prior to 3.0.6 and 2.6.3, cosign verify-blob-attestation may erroneously report a "Verified OK" result for attestations with malformed payloads or mismatched predicate types. For old-format bundles and detached signatures, this was due to a logic flaw in the error handling of the predicate type validation. For new-format bundles, the predicate type validation was bypassed completely. This vulnerability is fixed in 3.0.6 and 2.6.3.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- sigstore · cosign>= 3.0.0, < 3.0.6; < 2.6.3
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- sigstore
- Published
- April 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-39395 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.