{"id":"UBUNTU-CVE-2026-39395","details":"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.","modified":"2026-07-02T18:02:58.811526569Z","published":"2026-04-07T20:16:00Z","upstream":["CVE-2026-39395"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-39395"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-39395"},{"type":"REPORT","url":"https://github.com/sigstore/cosign/security/advisories/GHSA-w6c6-c85g-mmv6"}],"affected":[{"package":{"name":"cosign","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/cosign?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.4.3-1","2.5.0-2"],"ecosystem_specific":{"binaries":[{"binary_name":"cosign","binary_version":"2.5.0-2"},{"binary_name":"golang-github-sigstore-cosign-dev","binary_version":"2.5.0-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-39395.json"}},{"package":{"name":"cosign","ecosystem":"Ubuntu:Pro:26.04:LTS","purl":"pkg:deb/ubuntu/cosign?arch=source&distro=esm-apps%2Fresolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.5.0-2","2.5.0-2build1","2.6.2-1","2.6.2-1ubuntu0.26.04.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"cosign","binary_version":"2.6.2-1ubuntu0.26.04.1~esm1"},{"binary_name":"golang-github-sigstore-cosign-dev","binary_version":"2.6.2-1ubuntu0.26.04.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-39395.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}