# Kong Ingress Controller cross-namespace TLS Secret exfiltration

Source: https://junglewise.ai/threats/kong-ingress-controller-cross-namespace-tls-secret-exfiltration-9b867416  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-19. Updated: 2026-05-19  
License: CC BY 4.0 with a link back

Severity: medium · CVSS 5.6 · Published 2026-05-19

A vulnerability in the Kong Ingress Controller for Kubernetes allows users with limited permissions to access sensitive security credentials from other parts of the system. In multi-tenant environments, an attacker could steal TLS certificates and private keys belonging to other teams or applications. This could lead to unauthorized data decryption or the impersonation of secure services.

Technologies: [Kong Kubernetes Ingress Controller](https://junglewise.ai/threats/technologies/kubernetes-ingress-controller). Vendors: [Kong](https://junglewise.ai/threats/vendors/kong).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Medium severity, with a CVSS score of 5.6, published 19 May 2026.

**Which products and versions are affected?** Kong kubernetes-ingress-controller/v3 <= 3.4.13, >= 3.5.0, <= 3.5.6; Kong kubernetes-ingress-controller/v2 <= 2.12.8; Kong kubernetes-ingress-controller <= 1.3.4.

**Is there a fix for This vulnerability?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is This vulnerability attacked?** It is attacked over the network, in a software library.

**Am I affected?** Check whether you run Kong Kubernetes Ingress Controller. 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.

## Technical details

A vulnerability exists in the Kong Ingress Controller (KIC) Gateway TLS translator when operating in 'managed' mode (default). The translator fails to perform critical status checks and ReferenceGrant validation for cross-namespace certificate references. An attacker with RBAC permissions to create or update Gateway resources in a low-privileged namespace can reference a Secret in a high-privileged namespace. This causes KIC to fetch the Secret and include its private key material in the Kong dataplane configuration, bypassing intended namespace isolation. The fix introduces mandatory ReferenceGrant validation and requires a 'Programmed: True' listener status for cross-namespace access.

## Affected products

- Kong kubernetes-ingress-controller/v3 <= 3.4.13, >= 3.5.0, <= 3.5.6
- Kong kubernetes-ingress-controller/v2 <= 2.12.8
- Kong kubernetes-ingress-controller <= 1.3.4

## Timeline

- 2026-05-13: disclosed: Initial publication by maintainers
- 2026-05-19: advisory: GitHub Advisory published/updated

## References

- [https://api.github.com/users/bugbunny-research](https://api.github.com/users/bugbunny-research)
- [https://github.com/bugbunny-research](https://github.com/bugbunny-research)
- [https://api.github.com/users/bugbunny-research/gists%7B/gist_id%7D](https://api.github.com/users/bugbunny-research/gists%7B/gist_id%7D)
- [https://api.github.com/users/bugbunny-research/repos](https://api.github.com/users/bugbunny-research/repos)
- [https://avatars.githubusercontent.com/u/262839898?v=4](https://avatars.githubusercontent.com/u/262839898?v=4)
- [https://api.github.com/users/bugbunny-research/events%7B/privacy%7D](https://api.github.com/users/bugbunny-research/events%7B/privacy%7D)

## Related threats

- [Kong Kubernetes Ingress Controller denial of service via duplicate CA-certificate IDs](https://junglewise.ai/threats/cve-2026-15228-kong-kubernetes-ingress-controller-denial-of-service-via)
- [Kong Ingress Controller sensitive information leak in diagnostics endpoint](https://junglewise.ai/threats/kong-ingress-controller-sensitive-information-leak-in-diagnostics-6c22a38f)