Kyverno has SSRF via CEL http.Get/http.Post in NamespacedValidatingPolicy allows cross-namespace data access

Exploitation

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

CVSS

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

EPSS

• CVE-2026-4789: 0.71% estimated exploitation activity in the next 30 days; percentile 53.54 (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 A Server-Side Request Forgery (SSRF) vulnerability in Kyverno's CEL HTTP library (pkg/cel/libs/http/) allows users with namespace-scoped policy creation permissions to make arbitrary HTTP requests from the Kyverno admission controller. This enables unauthorized access to internal services in other namespaces, cloud metadata endpoints (169.254.169.254), and data exfiltration via policy error messages. Affected Versions - Kyverno = 1.16.0 (with policies.kyverno.io CRDs enabled, which is the default) - Tested on: Kyverno v1.16.2 (Helm chart 3.6.2) Details The http.Get() and http.Post() functions available in CEL-based policies (policies.kyverno.io API group) do not enforce any URL restrictions. Unlike resource.Lib which enforces namespace boundaries for namespaced policies, the http.Lib allows unrestricted access to any URL. Vulnerable Code: pkg/cel/libs/http/http.go Contrast with resource.Lib which enforces namespace: This is a different code path from previously reported…

Published by the source

14 Apr 2026, 22:37 UTC

Last modified by the source

5 Jul 2026, 18:26 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-rggm-jjmc-3394

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# Patch Next advisory brief: CVE-2026-4789

Advisory: Kyverno has SSRF via CEL http.Get/http.Post in NamespacedValidatingPolicy allows cross-namespace data access
IDs: CVE-2026-4789, GHSA-rggm-jjmc-3394
Record: https://patchnext.com/advisories/cve-2026-4789 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.5)
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 1.17.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/kyverno/kyverno: affected >= 1.16.0, < 1.17.0; fixed in 1.17.0

## 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://github.com/advisories/GHSA-rggm-jjmc-3394 (GitHub-reviewed advisory GHSA-rggm-jjmc-3394 lists affected ranges: Go github.com/kyverno/kyverno >=1.16.0 <1.17.0)

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