Vuln Signal Radar
public-safe defensive signal
HIGHpublic-safe

CVE-2026-86439

NVD: 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. NVD: Attackers can supply path arguments containing directory traversal sequences to access arbitrary Markdown files accessible to the server process. OSV: knowns before 0.30.0 Path Traversal via MCP doc and memory tools

CVSS
8.7
Severity
HIGH
EPSS
0.0075 (53)
KEV
-

Source-published summary

NVD: 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. NVD: Attackers can supply path arguments containing directory traversal sequences to access arbitrary Markdown files accessible to the server process. OSV: knowns before 0.30.0 Path Traversal via MCP doc and memory tools

Possible impact

Source describes path traversal review. Possible impact: An attacker may be able to reach files outside the intended application path.

Affected context

Affected product or version requires source confirmation.

Remediation / advisory

Remediation reference present; patch status requires confirmation in the linked advisory.

Why it matters

Source describes path traversal review. Possible impact: An attacker may be able to reach files outside the intended application path.; CVSS 8.7 (HIGH); EPSS percentile 53; not listed in KEV; Remediation reference present; patch status requires confirmation in the linked advisory; sources: NVD, OSV.

What to verify

Confirm affected product/version, vendor advisory, patch or mitigation, and exposure.

Exposure hint

exposure unknown

Impact tags

path traversal review

Urgency reasons

CVSS HIGHvendor advisory presentrecent updateremediation reference present

Source-derived note

Summary derived from NVD / OSV description; unsafe procedural detail is not shown.

Redaction metadata

source summary used
True
fallback summary used
False
unsafe procedural detail present
false
raw source displayed
false
public summary redacted
true

Remediation handoff

Public-safe static handoff for human/Codex remediation planning. Scan, patch, external execution, and auto remediation are disabled.

Safety note

This radar shows source-published defensive context only. Exploit procedures, exploit strings, scanner commands, and auto-remediation are not provided.

Official references