# CVE-2026-104120: modelcontextprotocol mcp-server-fetch/mcp-server-everything Fetch Tool server.py fetch_url server-side request forgery

> Attackers can exploit a server-side request forgery vulnerability in the fetch tool to access internal resources or bypass security controls.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Oct 2026
- **Updated:** 6 Oct 2026
- **Also known as:** GHSA-v78q-44mm-wf7q

## What is CVE-2026-104120?

CVE-2026-104120 is a medium-severity server-side request forgery vulnerability in modelcontextprotocol mcp-server-everything, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A security vulnerability has been detected in modelcontextprotocol mcp-server-fetch and mcp-server-everything up to 2026.6.4. Affected is the function fetch_url of the file mcp_server_fetch/server.py of the component Fetch Tool. The manipulation of the argument url/path leads to server-side request forgery. The attack may be initiated remotely. The exploit has been disclosed publicly and may be used. The pull request to fix this issue awaits acceptance.

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

## Which versions are affected by CVE-2026-104120?


## How do I fix CVE-2026-104120?

No fix has been published for CVE-2026-104120 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-104120 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-104120 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-104120 and fix it if it is affected.

What it is: CVE-2026-104120 is a medium-severity server-side request forgery vulnerability in modelcontextprotocol mcp-server-everything, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-104120 exists.

Affected product: modelcontextprotocol mcp-server-everything. 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-2026-104120/ (Markdown: https://insights.sbomify.com/CVE-2026-104120/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-104120
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104120
- OSV: https://osv.dev/vulnerability/CVE-2026-104120

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-104120/
Summaries are generated and may contain mistakes; the official description above is the record.