# CVE-2026-4789: Kyverno SSRF in CEL HTTP library functions

Source: https://junglewise.ai/threats/cve-2026-4789-kyverno-ssrf-in-cel-http-library-functions  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-14. Updated: 2026-07-05  
License: CC BY 4.0 with a link back

CVE-2026-4789 · Severity: high · CVSS 8.5 · Published 2026-04-14

Kyverno, a policy engine for Kubernetes, contains a security flaw that allows users with limited permissions to bypass security boundaries. By creating specific policies, an attacker can force the system to make unauthorized network requests to internal services or cloud provider metadata. This could lead to the theft of sensitive data, such as internal service credentials or cloud infrastructure access tokens, potentially compromising the entire cluster.

Technologies: [github.com/kyverno/kyverno (Go)](https://junglewise.ai/threats/technologies/github-com-kyverno-kyverno), [Kyverno](https://junglewise.ai/threats/technologies/kyverno). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Kyverno](https://junglewise.ai/threats/vendors/kyverno).

## Quick answers

**Is CVE-2026-4789 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-4789 being exploited in the wild.

**How severe is CVE-2026-4789?** High severity, with a CVSS score of 8.5, published 14 April 2026.

**Which products and versions are affected?** github.com/kyverno/kyverno (Go) >= 1.16.0, < 1.17.0, SEMVER:introduced=1.16.0,fixed=1.17.0; Kyverno >= 1.16.0, < 1.17.0.

**Is there a fix for CVE-2026-4789?** Yes. github.com/kyverno/kyverno (Go): upgrade to 1.17.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-4789 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-4789?** Check whether you run github.com/kyverno/kyverno (Go) or Kyverno at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/kyverno/kyverno (Go): upgrade to 1.17.0 or later

  ```sh
  go get github.com/kyverno/kyverno@v1.17.0
  ```


## Technical details

A Server-Side Request Forgery (SSRF) vulnerability exists in Kyverno's Common Expression Language (CEL) HTTP library within the `pkg/cel/libs/http/` component. The `http.Get()` and `http.Post()` functions fail to enforce URL restrictions or namespace boundaries, unlike other Kyverno libraries. An attacker with permissions to create namespaced policies (e.g., `NamespacedValidatingPolicy`) can craft a policy that executes HTTP requests to internal cluster services or cloud metadata endpoints (169.254.169.254). The results of these requests can be exfiltrated through policy validation error messages or audit logs. This issue is specific to the CEL-based policy implementation and was addressed in version 1.17.0.

## Affected products

- Kyverno Kyverno >= 1.16.0, < 1.17.0

## Identifiers

- CVE-2026-4789
- GHSA-rggm-jjmc-3394
- GO-2026-5621

## Timeline

- 2026-04-13: disclosed: Initial disclosure to maintainers
- 2026-04-14: advisory: GitHub Advisory published
- 2026-04-14: patched: Fix included in version 1.17.0

## References

- [https://api.github.com/users/iggypopi](https://api.github.com/users/iggypopi)
- [https://github.com/iggypopi](https://github.com/iggypopi)
- [https://api.github.com/users/iggypopi/gists%7B/gist_id%7D](https://api.github.com/users/iggypopi/gists%7B/gist_id%7D)
- [https://api.github.com/users/iggypopi/repos](https://api.github.com/users/iggypopi/repos)
- [https://avatars.githubusercontent.com/u/21137140?v=4](https://avatars.githubusercontent.com/u/21137140?v=4)
- [https://api.github.com/users/iggypopi/events%7B/privacy%7D](https://api.github.com/users/iggypopi/events%7B/privacy%7D)

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