PT-2026-64318 · Janhq · Jan

George Chen · CVE-2026-66005 · Published 2026-07-24 · Updated 2026-07-24

Mitre

CVSS v3.1

6.3

Medium

Base vector

AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L

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.

Exploit

Fix

Weakness Enumeration

CWE-183

CWE-942

Related Identifiers

CVE-2026-66005

Affected Products

Jan

References · 5

• 🔥 https://github.com/janhq/jan/issues/8453 · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-66005 · Security Note
• https://github.com/janhq/jan/commit/3e1c1e724f696620d89bb4a9cc18a380e0753757 · Patch
• https://vulncheck.com/advisories/jan-local-api-server-cors-origin-reflection-via-binding · Note
• https://github.com/janhq/jan/pull/8506 · Note