Vulnerability · Published Oct 12, 2026 · Assigned by VulnCheck

CVE-2026-109357LibreNMS before 26.9.0 LDAP Filter Injection Authentication Bypass via Authorization Header

High 8.1

In plain English

A high-severity security flaw in librenms from librenms. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.6%top 51.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

LibreNMS before 26.9.0 contains an LDAP filter injection in ldap-authorization and ad-authorization modes because usernames are inserted unescaped into LDAP search filters and authentication only checks user existence. When REMOTE_USER is not forwarded, unauthenticated attackers can send a wildcard username via HTTP Basic Authorization (PHP_AUTH_USER) to match all users and groups and gain admin access.

Affected products (as reported)

Vendor	Product	Versions
librenms	librenms	0 – before 26.9.0

Weakness: CWE-90 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

GitHub Security Advisory (GHSA-7cmx-65c5-8h8v) vendor-advisory
VulnCheck Advisory: LibreNMS before 26.9.0 LDAP Filter Injection Authentication Bypass via Authorization Header third-party-advisory