# CVE-2026-61559: @zereight/mcp-gitlab Vulnerable to Server-Side Request Forgery

> Attackers can redirect API calls to malicious hosts via a header, stealing victim tokens when dynamic API URL is enabled.

- **Severity:** Critical 9.6 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A: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:** 15 Sep 2026
- **Updated:** 17 Sep 2026
- **Also known as:** GHSA-2h44-8472-frjj

## What is CVE-2026-61559?

CVE-2026-61559 is a critical server-side request forgery vulnerability in zereight gitlab-mcp, published on 15 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

`@zereight/mcp-gitlab` is a Model Context Protocol server for GitLab. Starting in version 0.0.1 and prior to version 2.1.27, when the environment variable `ENABLE_DYNAMIC_API_URL=true` is set, the server reads the `X-GitLab-API-URL` HTTP request header and uses it as the base URL for all outbound GitLab API calls made within that request. The server validates that the value is a well-formed URL (`new URL(dynamicApiUrl)`) but applies no allowlist or hostname restriction. The server then attaches the victim's `Private-Token` to every outbound fetch that uses the redirected URL. Any caller who can reach the HTTP transport can set `X-GitLab-API-URL` to an attacker-controlled host. The next GitLab API call the server makes delivers the victim's token to that host. Version 2.1.27 contains a patch.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-61559?

2 open source packages ship an affected version, including @zereight/mcp-gitlab.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@zereight/mcp-gitlab` | npm | From 0.0.1 | 2.1.27 |
| `@zereight/mcp-gitlab` | npm | From 0.0.1 | 2.1.27 |

## How do I fix CVE-2026-61559?

Upgrade @zereight/mcp-gitlab to 2.1.27 or later.

## Is CVE-2026-61559 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-61559 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-61559 and fix it if it is affected.

What it is: CVE-2026-61559 is a critical server-side request forgery vulnerability in zereight gitlab-mcp, published on 15 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-61559 exists.

Affected packages and fixed versions:
- @zereight/mcp-gitlab (npm): affected from 0.0.1; fixed in 2.1.27
- @zereight/mcp-gitlab (npm): affected from 0.0.1; fixed in 2.1.27

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-2026-61559/ (Markdown: https://insights.sbomify.com/CVE-2026-61559/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-61559
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-61559
- OSV: https://osv.dev/vulnerability/CVE-2026-61559

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-61559/
Summaries are generated and may contain mistakes; the official description above is the record.