Critical · CVSS 9.2CVE-2026-109357

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

Answer in brief

CVE-2026-109357 records a Critical severity (CVSS 9.2) vulnerability in LibreNMS before 26.9.0 LDAP Filter Injection Authentication Bypass via Authorization Header. The current sources do not mark it as known exploited. The current feed maps librenms/librenms (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 12, 2026Updated Oct 12, 2026Source checked Oct 12, 2026First seen by HOL Oct 12, 2026Material review Oct 12, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.2
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 9.2. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps librenms/librenms (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
librenms/librenmsgeneric	>=0 <26.9.0	26.9.0

Recommended response

Check inventory. Check lockfiles and deployed manifests for librenms/librenms.
Review the reported fix. Update librenms/librenms to 26.9.0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 12, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 12, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 12, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.