Description
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 products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| sigstore | cosign | >= 3.0.0, < 3.0.6, < 2.6.3 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | cosign | 2.6.3-1 | — |
| Debian 13 | cosign | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | cosign | No fix yet | — |
| Ubuntu 25.10 | cosign | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 26.04 LTS | cosign | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | cosign | 3.0.6-150400.3.42.1 | SUSE-SU-2026:2365-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | cosign | 3.0.6-160000.1.1 | SUSE-SU-2026:22344-1 |
| SLES 16.0 | cosign | 3.0.6-160000.1.1 | SUSE-SU-2026:22344-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | cosign | 3.0.6-1.1 | openSUSE-SU-2026:10753-1 |
| openSUSE Leap 16.0 | cosign | 3.0.6-160000.1.1 | openSUSE-SU-2026:21036-1 |
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260723T184607-160000.1.1 | openSUSE-SU-2026:21483-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | cosign | 3.0.6-r0 | — |
| Alpine v3.23 | cosign | 2.6.3-r0 | — |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | aactl | 0.4.12-r55 | — |
| Wolfi rolling | crossplane-2.2 +1 | 2.2.3-r3 | — |
| Wolfi rolling | kubescape | 4.0.9-r5 | — |
| Wolfi rolling | kyverno-1.17 | 1.17.2-r35 | — |
| Wolfi rolling | kyverno-cli-1.17 +4 | 1.17.2-r14 | — |
| Wolfi rolling | kyverno-notation-aws | 1.1-r62 | — |
| Wolfi rolling | policy-controller +1 | 0.15.1-r14 | — |
| Wolfi rolling | ratify | 1.4.0-r36 | — |
| Wolfi rolling | ratify-licensechecker-compat | 1.4.5-r4 | — |
| Wolfi rolling | slsa-verifier | 2.7.1-r23 | — |
| Wolfi rolling | teleport-18.6-kube-agent-updater | 18.6.8-r28 | — |
| Wolfi rolling | trivy | 0.71.2-r2 | — |
| Wolfi rolling | trivy-operator | 0.30.1-r20 | — |
| Wolfi rolling | zot | 2.1.18-r1 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/sigstore/cosign | all versions | — | GO-2026-5694 |
| Go | github.com/sigstore/cosign | <= 1.13.6 | — | GHSA-w6c6-c85g-mmv6 |
| Go | github.com/sigstore/cosign/v2 | < 2.6.3 | 2.6.3 | GO-2026-5694 |
| Go | github.com/sigstore/cosign/v3 | >= 3.0.0, < 3.0.6 | 3.0.6 | GO-2026-5694 |
Advisories 5
- openSUSE-SU-2026:21483-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Jul 31, 2026
- SUSE-SU-2026:22344-1 Security update for cosign SUSE / openSUSE Security Updates · Jul 2, 2026
- openSUSE-SU-2026:21036-1 Security update for cosign SUSE / openSUSE Security Updates · Jun 30, 2026
- SUSE-SU-2026:2365-1 Security update for cosign SUSE / openSUSE Security Updates · Jun 12, 2026
- openSUSE-SU-2026:10753-1 cosign-3.0.6-1.1 on GA media SUSE / openSUSE Security Updates · May 13, 2026