CVE-2026-81835 RooCodeInc Roo-Code MCP Integration Trust Model malicious_mcp_server.py fetch_instructions code injection
Remote attackers can execute arbitrary code via the MCP integration trust model in the unsupported Roo-Code developer tool.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-81835?
CVE-2026-81835 is a medium-severity code injection vulnerability in RooCodeInc Roo-Code, published on 27 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
A security vulnerability has been detected in RooCodeInc Roo-Code up to 3.51.1. This affects the function fetch_instructions of the file malicious_mcp_server.py of the component MCP Integration Trust Model. The manipulation leads to code injection. The attack is possible to be carried out remotely. The exploit has been disclosed publicly and may be used. Multiple isses were reported to the vendor beforehand. They explain, that "they all apply to Roo Code, a project we no longer support - the repository was archived a while ago, and we don't encourage anyone to use it." This vulnerability only affects products that are no longer supported by the maintainer.
Which versions are affected by CVE-2026-81835?
How do I fix CVE-2026-81835?
No fix has been published for CVE-2026-81835 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-81835 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-81835 exists.
Sources
Also known as GHSA-q2jq-8pm2-fj8h.