# CVE-2026-65601: Traefik before 3.7.7 Namespace Confusion via HTTPRoute ExtensionRef

> Traefik allows low-privileged users to inject headers by bypassing namespace checks in Kubernetes Gateway API configurations.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/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:** Yes
- **Published:** 22 Jul 2026
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-qq9q-x9w4-chhj, GO-2026-6198, MINI-8w5m-65pq-3vfw, MINI-chpq-j4gc-rh8x

## What is CVE-2026-65601?

CVE-2026-65601 is a medium-severity missing authorization vulnerability in Traefik Traefik, published on 22 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Traefik versions 3.7.0 through 3.7.6 contain a namespace confusion vulnerability in the Kubernetes Gateway API provider. When resolving HTTPRoute.spec.rules[].backendRefs[].filters[].extensionRef, Traefik used the backend Service namespace instead of the HTTPRoute namespace. A low-privileged route author holding a ReferenceGrant for a cross-namespace Service could therefore bind a Traefik Middleware from the backend namespace without a separate grant for that middleware, potentially injecting trusted reverse-proxy identity headers into downstream requests. The issue is fixed in version 3.7.7.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-65601?

3 open source packages ship an affected version, including Traefik and github.com/traefik/traefik. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `Traefik` | Go | From 3.7.0 | 3.7.7 |
| `Traefik` | Go | From 3.7.0 | 3.7.7 |
| `github.com/traefik/traefik` | Go | All versions | None |

Products: Traefik Traefik.

## How do I fix CVE-2026-65601?

Upgrade Traefik to 3.7.7 or later.

## Is CVE-2026-65601 being exploited?

There is no known exploitation of CVE-2026-65601 in the wild and no public exploit code.

## Other vulnerabilities in Traefik Traefik

- [CVE-2024-45410](https://insights.sbomify.com/CVE-2024-45410/): HTTP client can remove the X-Forwarded headers in Traefik (critical 9.8)
- [CVE-2026-88877](https://insights.sbomify.com/CVE-2026-88877/): Traefik v3.7.0 Authentication Bypass via from-to-www-redirect (critical 9.3)
- [CVE-2026-85595](https://insights.sbomify.com/CVE-2026-85595/): Traefik before v2.11.55 and v3.0.0 through v3.7.10 Authentication Bypass via digestAuth (critical 9.3)
- [CVE-2026-88007](https://insights.sbomify.com/CVE-2026-88007/): Traefik HTTP/3 Backend NTLM Connection Reuse (critical 9.1)
- [CVE-2026-88009](https://insights.sbomify.com/CVE-2026-88009/): Traefik: Rootless HTTP/1 request-target routes as "/" but is forwarded verbatim, bypassing path-scoped routing, middleware guards and access logging (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-65601 and fix it if it is affected.

What it is: CVE-2026-65601 is a medium-severity missing authorization vulnerability in Traefik Traefik, published on 22 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-2026-65601 in the wild and no public exploit code.

Affected packages and fixed versions:
- Traefik (Go): affected from 3.7.0; fixed in 3.7.7
- Traefik (Go): affected from 3.7.0; fixed in 3.7.7
- github.com/traefik/traefik (Go): affected all versions; no fix listed

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-2026-65601/ (Markdown: https://insights.sbomify.com/CVE-2026-65601/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-65601
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-65601
- OSV: https://osv.dev/vulnerability/CVE-2026-65601

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-65601/
Summaries are generated and may contain mistakes; the official description above is the record.