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.
Published: 2026-10-12
Score: 9.2 Critical
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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Advisories

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History

Mon, 12 Oct 2026 16:30:00 +0000

Type Values Removed Values Added
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.
Title LibreNMS before 26.9.0 LDAP Filter Injection Authentication Bypass via Authorization Header
First Time appeared Librenms
Librenms librenms
Weaknesses CWE-90
CPEs cpe:2.3:a:librenms:librenms:*:*:*:*:*:*:*:*
Vendors & Products Librenms
Librenms librenms
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


Subscriptions

Librenms Librenms
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-12T16:05:37.653Z

Reserved: 2026-10-12T14:21:32.594Z

Link: CVE-2026-109357

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-12T17:17:33.020

Modified: 2026-10-12T17:17:33.020

Link: CVE-2026-109357

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-90

    Improper Neutralization of Special Elements used in an LDAP Query ('LDAP Injection')