# CVE-2026-55723: NGINX Ingress Controller vulnerability

> Authenticated attackers can inject arbitrary NGINX directives via unsanitized CRDs or annotations, potentially executing code or modifying files.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Jul 2026
- **Updated:** 16 Jul 2026
- **Also known as:** GHSA-wxxq-mwhh-cvm2

## What is CVE-2026-55723?

CVE-2026-55723 is a high-severity code injection vulnerability in F5 NGINX Ingress Controller, published on 15 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

When NGINX Ingress Controller is configured with Custom Resource Definitions (CRDs) or Ingress annotations, an injection vulnerability exists in the configuration generator of NGINX Ingress Controller. Multiple user-controllable fields are written into the generated NGINX configuration without sanitization. An authenticated attacker with permission to create or modify these CRDs or annotations may craft values that inject arbitrary NGINX configuration directives. 

Impact:
An authenticated attacker granted write access to NGINX Ingress Controller CRDs or Ingress annotations through the Kubernetes API may be able to inject arbitrary NGINX configuration directives, create or delete files, or disable services. There is no data plane exposure; this is a control plane issue only.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Weakness: CWE-76 (Improper Neutralization of Equivalent Special Elements)

## Which versions are affected by CVE-2026-55723?

It affects 1 product.


Products: F5 Nginx Ingress Controller.

## How do I fix CVE-2026-55723?

No fix has been published for CVE-2026-55723 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-55723 being exploited?

There is no known exploitation of CVE-2026-55723 in the wild and no public exploit code.

## Other vulnerabilities in F5 NGINX Ingress Controller

- [CVE-2025-14727](https://insights.sbomify.com/CVE-2025-14727/): NGINX Ingress Controller vulnerability (high 8.7)
- [CVE-2026-52865](https://insights.sbomify.com/CVE-2026-52865/): NGINX Ingress Controller vulnerability (high 7.1)
- [CVE-2022-41743](https://insights.sbomify.com/CVE-2022-41743/): NGINX ngx_http_hls_module vulnerability CVE-2022-41743 (high 7.0)
- [CVE-2022-30535](https://insights.sbomify.com/CVE-2022-30535/): NGINX Ingress Controller vulnerability CVE-2022-30535 (medium 6.5)
- [CVE-2021-23055](https://insights.sbomify.com/CVE-2021-23055/): Security feature bypass in NGINX Ingress Controller (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55723 and fix it if it is affected.

What it is: CVE-2026-55723 is a high-severity code injection vulnerability in F5 NGINX Ingress Controller, published on 15 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-55723 in the wild and no public exploit code.

Affected product: F5 NGINX Ingress Controller. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-55723/ (Markdown: https://insights.sbomify.com/CVE-2026-55723/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55723
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55723
- OSV: https://osv.dev/vulnerability/CVE-2026-55723

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55723/
Summaries are generated and may contain mistakes; the official description above is the record.