---
title: "CVE-2026-54523: Kyverno's NamespacedGeneratingPolicy generator.apply() namespace argument unvalidated -- background controller creates RoleBindings in any namespace including kube-system"
url: https://erroneo.us/security/cve/CVE-2026-54523/
description: "CVE-2026-54523 (github.com/kyverno/kyverno (Go)): Kyverno is a policy engine designed for cloud native platform engineering teams. From 1.18.0 until 1.18.2…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-08-26
date_modified: 2026-08-26
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-54523"
kev: false
cvss: 9.6
epss: 0.00466
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-54523: Kyverno's NamespacedGeneratingPolicy generator.apply() namespace argument unvalidated -- background controller creates RoleBindings in any namespace including kube-system

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.5% , percentile 39: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 39% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes github.com/kyverno/kyverno (Go) >= 1.18.0, <= 1.18.1, fixed in 1.18.2 . Check your lockfile, including transitive dependencies.

## What it is

Kyverno is a policy engine designed for cloud native platform engineering teams. From 1.18.0 until 1.18.2, the NamespacedMutatingPolicy CEL compiler exposes the generator library to matchConditions, allowing a namespace-scoped policy to invoke generator.apply(namespace, resources) with an arbitrary target namespace. The validation in pkg/cel/policies/mpol/validate.go checks that the policy compiles but does not enforce namespace scope, and GenerateResources in pkg/cel/libs/context.go does not reject the cross-namespace target. A user who can create NamespacedMutatingPolicy objects in one namespace can cause the admission controller, operating with cluster-wide privileges, to create ConfigMaps, NetworkPolicies, Secrets, RoleBindings, and other resources in another namespace, enabling unauthorized modification and potential privilege escalation. This issue is fixed in version 1.18.2.

## Affected packages

- Go `github.com/kyverno/kyverno` >= 1.18.0, <= 1.18.1 → fixed: 1.18.2

## Affected products (CVE record)

- kyverno kyverno: >= 1.18.0, < 1.18.2

## Severity

- GitHub_M CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`
- GitHub CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.47% probability of exploitation activity in the next 30 days; percentile 39.

## Sources

- [GitHub Advisory GHSA-79gf-7frw-68m9](https://github.com/advisories/GHSA-79gf-7frw-68m9)
- [CVE.org record CVE-2026-54523](https://www.cve.org/CVERecord?id=CVE-2026-54523)
- [NVD entry CVE-2026-54523](https://nvd.nist.gov/vuln/detail/CVE-2026-54523)
- [github.com](https://github.com/kyverno/kyverno/security/advisories/GHSA-79gf-7frw-68m9)
- [github.com](https://github.com/kyverno/kyverno/pull/16238)
- [github.com](https://github.com/kyverno/kyverno/commit/0919553c0ea1904f8d891280c92018da97946a06)
- [github.com](https://github.com/kyverno/kyverno/commit/5164bcdeda5b57678bc2d7a03ecc2cbb02982dae)
- [github.com](https://github.com/kyverno/sdk/commit/6573937441443e1ba5af9fbb28d5c0f20297f9df)
- [github.com](https://github.com/kyverno/kyverno/releases/tag/v1.18.2)

---
Source page: https://erroneo.us/security/cve/CVE-2026-54523/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt