# CVE-2026-37236: Security feature bypass in n/a

> Attackers can bypass method-based access controls in grpc-gateway by using the X-HTTP-Method-Override header to rewrite request methods.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 28 Aug 2026
- **Updated:** 2 Sep 2026
- **Also known as:** AZL-98253, AZL-98256, AZL-98343, AZL-98346, AZL-98349, AZL-98352, AZL-98355, AZL-98358, AZL-98361, AZL-98364, AZL-98367, AZL-98373, AZL-98376, AZL-98379, AZL-98385, AZL-98388, AZL-98391, AZL-98394, AZL-98436, DEBIAN-CVE-2026-37236, GHSA-6gx8-r37x-4vw8, UBUNTU-CVE-2026-37236, openSUSE-SU-2026:11669-1

## What is CVE-2026-37236?

CVE-2026-37236 is a critical vulnerability in n/a, published on 28 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

grpc-gateway v2.28.0 is vulnerable to Incorrect Access Control. The application processes the X-HTTP-Method-Override header in ServeMux.ServeHTTP without restricting allowed methods. When a POST request with Content-Type application/x-www-form-urlencoded includes this header, the request method is rewritten to an arbitrary attacker-supplied value before routing. This allows bypassing method-based access controls enforced by upstream proxies or WAFs.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2026-37236?


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `helm3` | openSUSE:Tumbleweed | All versions | 3.21.3-7.1 |

## How do I fix CVE-2026-37236?

Upgrade to a fixed version.

## Is CVE-2026-37236 being exploited?

There is no known exploitation of CVE-2026-37236 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-37236 and fix it if it is affected.

What it is: CVE-2026-37236 is a critical vulnerability in n/a, published on 28 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-37236 in the wild and no public exploit code.

Affected product: n/a. 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-2026-37236/ (Markdown: https://insights.sbomify.com/CVE-2026-37236/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-37236
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-37236
- OSV: https://osv.dev/vulnerability/CVE-2026-37236

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-37236/
Summaries are generated and may contain mistakes; the official description above is the record.