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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.6 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

EPSS

• CVE-2026-54523: 0.47% estimated exploitation activity in the next 30 days; percentile 40.39 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary In Kyverno v1.18.1, a tenant who can create a NamespacedMutatingPolicy in their own namespace can instruct the admission controller to generate resources in any namespace by passing an arbitrary namespace string to the CEL generator.apply(namespace, resources) function. Details pkg/cel/libs/context.go:177 declares GenerateResources(namespace string, dataList []map[string]any). The namespace argument arrives unvalidated from the CEL expression generator.apply("<target-namespace", [...]). Version-Specific Impact v1.18.0, v1.18.1 (affected via NamespacedMutatingPolicy only): The nmpol CEL compiler unintentionally exposes the generator library to match condition expressions. A namespaced mutating policy can invoke generator.apply() in a boolean CEL expression such as matchConditions, triggering the admission controller to generate resources in any namespace at request time. This side effect executes with the admission controller's cluster-wide privileges.…

Published by the source

26 Aug 2026, 14:21 UTC

Last modified by the source

2 Sep 2026, 16:25 UTC

Source last checked

26 Oct 2026, 15:28 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-79gf-7frw-68m9

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6296

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-79gf-7frw-68m9

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# Patch Next advisory brief: CVE-2026-54523

Advisory: Kyverno's NamespacedGeneratingPolicy generator.apply() namespace argument unvalidated -- background controller creates RoleBindings in any namespace including kube-system
IDs: CVE-2026-54523, GHSA-79gf-7frw-68m9
Record: https://patchnext.com/advisories/cve-2026-54523 (revision 3, source checked 26 Oct 2026, 15:28 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/kyverno/kyverno 1.18.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/kyverno/kyverno: affected >= 1.18.0, <= 1.18.1; fixed in 1.18.2

## Suggested inspection (read-only)
- Go github.com/kyverno/kyverno: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/kyverno/kyverno.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-79gf-7frw-68m9 (OSV record GHSA-79gf-7frw-68m9 lists affected ranges: Go github.com/kyverno/kyverno >=1.18.0 <1.18.2 (fixed))
- Verified: https://osv.dev/vulnerability/GO-2026-6296 (OSV record GO-2026-6296 lists affected ranges: Go github.com/kyverno/kyverno >=1.18.0 <1.18.2 (fixed))
- Verified: https://github.com/advisories/GHSA-79gf-7frw-68m9 (GitHub-reviewed advisory GHSA-79gf-7frw-68m9 lists affected ranges: Go github.com/kyverno/kyverno >=1.18.0 <=1.18.1)

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