CVE-2026-86426

Critical

Description

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.

SeverityCritical

CVSS9.8

Exploit probability—

ProductLibrenms

PublishedSep 7, 2026

First seenSep 7, 2026

Weakness typeCWE-287Improper authentication

How to fix

Update

librenms librenms26.8.0 or later

Vendor advisories

github.com/librenms/librenms/security/advisories/GHSA-cvq8-gqfq-3mvg

Affected products

Product	Affected versions	Fixed in
librenms librenms	v < 26.8.0	26.8.0

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