CVE-2026-39395

EUVD-2026-19919
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
4.3 MEDIUM
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 12%
Affected Products (NVD)
VendorProductVersion
sigstorecosign
𝑥
< 2.6.3
sigstorecosign
3.0.0 ≤
𝑥
< 3.0.6
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
cosign
forky
2.6.3-1
fixed
sid
2.6.3-1
fixed
trixie
no-dsa
golang-github-sigstore-cosign-v2
forky
2.6.3-2
fixed
sid
2.6.3-2
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
cosign
jammy
dne
noble
dne
questing
needs-triage
resolute
needs-triage