CVE-2026-66005

Summary

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 Software

VendorProductVersion RangeStatus
janhqjan0 <= 0.8.4affected
janhqjan3e1c1e724f696620d89bb4a9cc18a380e0753757unaffected

Weaknesses

  • CWE-183: Permissive List of Allowed Inputs
  • CWE-942: Permissive Cross-domain Security Policy with Untrusted Domains

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: partial

References