What is CVE-2022-36056?

CVE-2022-36056 is a medium-severity vulnerability in Sigstore Cosign, classified under Improper Verification of Cryptographic Signature. CVSS score: 5.5/10. Published 2022-09-14.

How severe is CVE-2022-36056?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Vulnerability in Sigstore Cosign

CVE-2022-36056

Cosign is a project under the sigstore organization which aims to make signatures invisible infrastructure. In versions prior to 1.12.0 a number of vulnerabilities have been found in cosign verify-blob, where Cosign would successfully verify an artifact when verification should have failed. First a cosign bundle can be crafted to successfully verify a blob even if the embedded rekorBundle does not reference the given signature. Second, when providing identity flags, the email and issuer of a certificate is not checked when verifying a Rekor bundle, and the GitHub Actions identity is never checked. Third, providing an invalid Rekor bundle without the experimental flag results in a successful verification. And fourth an invalid transparency log entry will result in immediate success for verification. Details and examples of these issues can be seen in the GHSA-8gw7-4j42-w388 advisory linked. Users are advised to upgrade to 1.12.0. There are no known workarounds for these issues.

Published 2022-09-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.002 (3.5th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 3.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000

Affected products

Sigstore Cosign — versions < 1.12.0

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

References

github.com/sigstore/cosign/security/advisories/GHSA-8gw7-4j42-w388 (Exploit, Patch, Third Party Advisory, Mitigation)
github.com/sigstore/cosign/commit/80b79ed8b4d28ccbce3d279fd273606b5cddcc25 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2022-36056?: CVE-2022-36056 is a medium-severity vulnerability in Sigstore Cosign, classified under Improper Verification of Cryptographic Signature. CVSS score: 5.5/10. Published 2022-09-14.
How severe is CVE-2022-36056?: Medium severity. CVSS v3 base score is 5.5 out of 10.