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.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
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
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.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-104120 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-104120 exists.
Sources
Also known as GHSA-v78q-44mm-wf7q.