CVE-2026-66005

MediumCVSS 6.3

Published: 24/07/2026(UTC)Updated: 24/10/2026(UTC)Translated: 25/07/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.33%

25th percentile - higher than 25% of all known CVEs

Summary

Vulnerability in Jan up to version 0.8.4 due to a CORS misconfiguration in the local API server. The server replaces trusted hosts with a wildcard, allowing network-adjacent attackers to access the unauthenticated OpenAI-compatible API.

Risk Assessment

An attacker can perform inference, enumerate models, invoke MCP tools, and read cross-origin responses, leading to data leakage and unauthorized resource usage.

Recommendation

Update Jan to the fixed version (commit 3e1c1e7) and configure CORS to avoid using a wildcard for trusted hosts.

Other vulnerabilities in Jan

CVE-2026-122235Medium
Jan from 0.8.5 before 0.8.8 contains a workspace guard bypass vulnerability in the agent-tools gate.rs that allows attackers to write files outside the workspace via dangling symlinks. Attackers supplying a malicious repository can use prompt injection to make the write or edit tools follow symlinks, creating files like ~/.ssh/authorized_keys on the host.

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS