CVE-2022-35929: False positive signature verification in cosign

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2022-08-04 · updated 2026-06-17
Weakness: CWE-347

Description

cosign is a container signing and verification utility. In versions prior to 1.10.1 cosign can report a false positive if any attestation exists. `cosign verify-attestation` used with the `--type` flag will report a false positive verification when there is at least one attestation with a valid signature and there are NO attestations of the type being verified (--type defaults to "custom"). This can happen when signing with a standard keypair and with "keyless" signing with Fulcio. This vulnerability can be reproduced with the `distroless.dev/static@sha256:dd7614b5a12bc4d617b223c588b4e0c833402b8f4991fb5702ea83afad1986e2` image. This image has a `vuln` attestation but not an `spdx` attestation. However, if you run `cosign verify-attestation --type=spdx` on this image, it incorrectly succeeds. This issue has been addressed in version 1.10.1 of cosign. Users are advised to upgrade. There are no known workarounds for this issue.

Affected products

sigstore cosign: before 1.10.1 — fixed in 1.10.1

How to fix

Upgrade to a fixed version: sigstore cosign 1.10.1. Check the vendor advisory for mitigations.

References

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