CVE-2026-66005
Jan Local API Server CORS Origin Reflection via 0.0.0.0 Binding
MEDIUM 5.3EPSS 0.3%
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
- janhq · jan
- CVSS v4.0 VULNCHECK
- 5.3 MEDIUM
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS v3.1 VULNCHECK
- 6.3 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L - EPSS
- 0.33% chance of exploitation in the next 30 days, 25th percentile
- Published
- 2026-07-24
- Updated
- 2026-09-17
Proof-of-concept exploits (1)
- janhq/jan/issues/845344938★ · 2026-10-14