CVE-2026-109357

LibreNMS before 26.9.0 LDAP Filter Injection Authentication Bypass via Authorization Header

HIGH
8.1
CVSS Score
Published: October 12, 2026 at 04:05 PM UTC
Updated: October 15, 2026 at 08:33 PM UTC
1 product affected across 1 vendorLibrenms

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Severity
HIGH8.1
Exploit prediction
EPSS 0.6%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

0
Vendor states this is fixed in 26.9.0 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.1HIGHVulnCheck
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-90

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