CVE-2026-86439

knowns before 0.30.0 Path Traversal via MCP doc and memory tools

Published Sep 7, 2026 CVSS 4.0 · 8.7 High EPSS 1.1% KEV · Not listed
Description
knowns versions before 0.30.0 fail to validate filesystem paths in MCP tool arguments, allowing attackers to read, create, overwrite and delete files outside the project directory. Attackers can supply path arguments containing directory traversal sequences to access arbitrary Markdown files accessible to the server process.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-9gfj-28hw-jchp Knowns Unrestricted Path Traversal leading to out-of-bounds arbitrary .md file read, write, and deletion in MCP Docs + Memory Tools
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Knowns-dev
Knowns-dev knowns
Vendors & Products Knowns-dev
Knowns-dev knowns
Type Values Removed Values Added
Description knowns versions before 0.30.0 fail to validate filesystem paths in MCP tool arguments, allowing attackers to read, create, overwrite and delete files outside the project directory. Attackers can supply path arguments containing directory traversal sequences to access arbitrary Markdown files accessible to the server process.
Title knowns before 0.30.0 Path Traversal via MCP doc and memory tools
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 24, 2026, 2:21 PM
Reserved
Sep 7, 2026, 12:34 PM
Status
Deferred
Published
Sep 7, 2026, 11:16 PM
Modified
Sep 8, 2026, 7:56 PM