CVE-2026-66005: Janhq Jan

Medium severity, CVSS 6.3. EPSS: 0.3% chance of exploitation in the next 30 days.

Jan through 0.8.4, fixed in commit 3e1c1e7, contains a CORS misconfiguration vulnerability in its local API server that allows network-adjacent attackers to bypass trusted host restrictions by exploiting the server's replacement of user-configured trusted hosts with a wildcard that reflects arbitrary origins with credentials. Attackers on the local network or using DNS rebinding can reach the unauthenticated OpenAI-compatible API to perform inference, enumerate models, invoke MCP tools, and read cross-origin responses.

Affected products

• Janhq Jan: up to and including 0.8.4

Published 2026-07-24. Last modified 2026-09-17.