CVE-2026-86439
highknowns versions before 0.30.0 fail to validate filesystem paths in MCP tool arguments, allowing attackers to read, create, overwrite and delete files outside t…
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
8.8
8.8 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Severity source: NVD CVSS v3.1 (disclosure@vulncheck.com)
Timeline (UTC)
Published: 2026-09-07 23:16
Modified: 2026-09-08 19:56
NVD status: Deferred
Last synced 1 day ago
Verified against the source API 2026-10-27 06:51 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/storage/doc_store.go#L124-L129 disclosure@vulncheck.com
- https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/storage/memory_store.go#L203-L2... disclosure@vulncheck.com
- https://github.com/knowns-dev/knowns/commit/09c5a96fd5817b941dc86669278c1a17db10ed4e disclosure@vulncheck.com
- https://github.com/knowns-dev/knowns/releases/tag/v0.30.0 disclosure@vulncheck.com
- https://github.com/knowns-dev/knowns/security/advisories/GHSA-9gfj-28hw-jchp disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/knowns-before-0.30.0-path-traversal-via-mcp-doc-and-m... disclosure@vulncheck.com
Data sources
NVD CVE API 2.0 — fetched 2026-10-27 06:51 UTC · record ↗