CVE-2026-66005

Name of the Vulnerable Software and Affected Versions Jan versions prior to 0.8.4

Description A CORS (Cross-Origin Resource Sharing) misconfiguration in the local API server allows network-adjacent attackers to bypass trusted host restrictions. This occurs because the server replaces user-configured trusted hosts with a wildcard that reflects arbitrary origins with credentials. Attackers on the local network or those using DNS rebinding—a technique that tricks a browser into thinking a malicious site is a trusted one—can access the unauthenticated OpenAI-compatible API to perform inference, enumerate models, invoke MCP tools, and read cross-origin responses.

Recommendations Update Jan to a version that includes the fix implemented in commit 3e1c1e7.