CVE-2026-86541
CVE-2026-86541
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.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:H.
EPSS exploit prediction
EPSS: 0.008 (55.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.008 · change: +0.002
Weakness classification (CWE)
References
- handleCodeReplace resolves and writes the caller-supplied path without containment (v0.29.1) (technical-description)
- knowns fix commit a2c98fc5c313 (patch)
- knowns v0.30.0 Release Notes (release-notes)
- GitHub Security Advisory (GHSA-f539-xgc6-xw7q) (vendor-advisory)
- VulnCheck Advisory: knowns before 0.30.0 Path Traversal via code.replace MCP action (third-party-advisory)
Frequently asked questions
- What is CVE-2026-86541?
- CVE-2026-86541 is a high-severity vulnerability, classified under Path Traversal. CVSS score: 8.3/10. Published 2026-09-07.
- How severe is CVE-2026-86541?
- High severity. CVSS v3 base score is 8.3 out of 10.