CVE-2026-86541 knowns before 0.30.0 Path Traversal via code.replace MCP action
Attackers can overwrite arbitrary files outside the project root via path traversal in the code.replace action, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-86541?
CVE-2026-86541 is a high-severity path traversal vulnerability in knowns-dev knowns, published on 7 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
knowns versions before 0.30.0 contain a path traversal vulnerability in the handleCodeReplace() function that allows attackers to overwrite arbitrary files outside the project root. Attackers can supply absolute paths or relative paths containing directory traversal sequences to write malicious content to sensitive files like shell startup scripts or SSH configuration files.
Weakness: CWE-22
Which versions are affected by CVE-2026-86541?
How do I fix CVE-2026-86541?
No fix has been published for CVE-2026-86541 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-86541 being exploited?
There is no known exploitation of CVE-2026-86541 in the wild and no public exploit code.
Sources
Also known as GHSA-f539-xgc6-xw7q, GHSA-g6q2-h5cf-8q26.