CVE-2026-86426: Librenms

Critical severity, CVSS 9.8. EPSS: 3.9% chance of exploitation in the next 30 days.

LibreNMS before 26.8.0 contains an authentication bypass vulnerability in the REST API that allows unauthenticated attackers to access protected endpoints by sending numeric values instead of string tokens. Attackers can exploit MySQL type coercion by sending small integers like 0 through 9 to match token hashes, gaining access to API functionality including device credentials and administrative features that enable remote code execution through alert templates.

Affected products

• Librenms Librenms: before 26.8.0 (fixed in 26.8.0)

Published 2026-09-07. Last modified 2026-09-18.