# CVE-2026-122321: Kyverno verifyImages signature verification bypass via cache

Source: https://junglewise.ai/threats/cve-2026-122321-kyverno-1-18-0-before-1-19-2-contains-a-signature-verification  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-05. Updated: 2026-11-05  
License: CC BY 4.0 with a link back

CVE-2026-122321 · Severity: critical · CVSS 9.1 · Published 2026-11-05

Kyverno is a policy engine that validates container images in Kubernetes clusters to ensure they are signed and trustworthy. This vulnerability allows an attacker who can move container image tags in a registry to bypass image verification by exploiting a caching flaw, causing Kyverno to admit unverified container images into the cluster. An attacker could use this to deploy malicious or tampered container images, potentially gaining unauthorized access to the cluster and its data.

Technologies: [Kyverno](https://junglewise.ai/threats/technologies/kyverno). Vendors: [Kyverno](https://junglewise.ai/threats/vendors/kyverno).

## Quick answers

**Is CVE-2026-122321 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-122321 being exploited in the wild.

**How severe is CVE-2026-122321?** Critical severity, with a CVSS score of 9.1, published 5 November 2026.

**Which products and versions are affected?** Kyverno 1.18.0 to 1.19.1.

**Is there a fix for CVE-2026-122321?** Yes: fixed in 1.19.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-122321 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-122321?** Check whether you run Kyverno at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 1.19.2

## Technical details

The verifyImages cache stores verification results using the image reference string (such as a tag) as the key but does not bind the cached result to the verified digest. On a cache hit, the Verify function returns a pass response without re-running signature or attestation verification, and then mutateDigest can pin an unverified digest without re-verification. An attacker with registry tag manipulation capabilities can verify a signed image once to warm the cache, then move the tag to a different (unsigned) digest, and Kyverno will admit the workload from cache while pinning the unverified digest.

## Affected products

- Kyverno Kyverno 1.18.0 to 1.19.1

## Timeline

- 2026-10-21: disclosed
- 2026-11-05: advisory

## References

- [https://github.com/kyverno/kyverno/security/advisories/GHSA-2r43-6962-xcw5](https://github.com/kyverno/kyverno/security/advisories/GHSA-2r43-6962-xcw5)
- [https://www.vulncheck.com/advisories/kyverno-1.18.0-before-1.19.2-verifyimages-cache-signature-verification-bypass](https://www.vulncheck.com/advisories/kyverno-1.18.0-before-1.19.2-verifyimages-cache-signature-verification-bypass)

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