---
id: "CVE-2026-122305"
kind: "vulnerability"
aliases: ["CVE-2026-122305"]
title: "Kyverno: self-referential variables let low-privileged users hang admission webhook"
severity: "high"
cvss: 8.3
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "kubernetes", "kyverno", "self-hosted"]
not_affected_if: ["kyverno-not-installed", "version-1.19.2-or-later"]
published_at: "2026-11-05T03:17:22+00:00"
first_seen_at: "2026-11-05T03:31:41+00:00"
updated_at: "2026-11-05T03:33:22+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-122305", "first_seen_at": "2026-11-05T03:31:41+00:00"}]
exploit_sources: []
---

# Kyverno: self-referential variables let low-privileged users hang admission webhook

Kyverno before 1.19.2 loops without bound when a resource's annotations re-introduce a policy variable into substitution, which exhausts CPU and memory. An attacker with low privileges can create such a resource and block cluster-wide admission.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed Kyverno version with `kubectl get deploy -n kyverno kyverno-admission-controller -o jsonpath='{.spec.template.spec.containers[0].image}'`
- Confirm whether your Kyverno version is below `1.19.2`

## Fix

- Kyverno: move to `1.19.2` or later

## Timeline

- 2026-11-05T03:31:41+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-122305

## Documents

- [advisory] Vendor advisory: github.com https://github.com/kyverno/kyverno/security/advisories/GHSA-338x-hgrv-626h
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/kyverno-before-1.19.2-denial-of-service-via-nested-variable-substitution-loop

## From the sources

Kyverno before 1.19.2 contains a denial of service vulnerability in substituteVariablesIfAny that allows low-privileged users to hang the admission webhook via self-referential variable templates. Attackers can create resources whose annotations re-introduce the embedded policy variable, causing unbounded substitution loops that exhaust CPU and memory and block cluster-wide admission.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_