CVE-2026-86439
CVE-2026-86439 · knowns before 0.30.0 Path Traversal via MCP doc and memory tools
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 8.7 · High · EPSS 1.1% · Fix available
- Published
- Updated
Stack: node
Affected products and versions
Original sources
- https://github.com/knowns-dev/knowns/security/advisories/GHSA-9gfj-28hw-jchp
- https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/storage/doc_store.go#L124-L129
- https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/storage/memory_store.go#L203-L211
- https://github.com/knowns-dev/knowns/commit/09c5a96fd5817b941dc86669278c1a17db10ed4e
- https://github.com/knowns-dev/knowns/releases/tag/v0.30.0
- https://www.vulncheck.com/advisories/knowns-before-0.30.0-path-traversal-via-mcp-doc-and-memory-tools
- https://nvd.nist.gov/vuln/detail/CVE-2026-86439