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TI-2026-71173 Aliases CVE-2026-109357GHSA-rx4g-rhf6-xw5x

LDAP filter injection in LibreNMS allows authentication bypass

Priority HIGH 75CWE-90Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

LibreNMS before 26.9.0 contains an LDAP filter injection in its ldap-authorization and ad-authorization modes. Usernames are inserted unescaped into LDAP search filters, and authentication only checks that the user exists. When REMOTE_USER is not forwarded, an unauthenticated remote attacker can send a wildcard username through HTTP Basic Authorization to match all users and groups and gain admin access. The weakness is classified as CWE-90.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00596 48th percentileScored 2026-11-07
Fix Fixed librenms (librenms): 26.9.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
librenmslibrenmsbefore 26.9.026.9.0Patch availableCNA
  • librenms Vendorlibrenms Affected before 26.9.0 Fixed in 26.9.0 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:librenms:librenms:*:*:*:*:*:*:*:*——librenms
  • cpe:2.3:a:librenms:librenms:*:*:*:*:*:*:*:* Versions — — ·librenms

Remediation

Update LibreNMS to version 26.9.0 or later, which fixes the flaw.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA librenms (librenms) Fixed in 26.9.0

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    librenms 26.9.0

    6 records Highest priority Priority HIGH 1 HIGH, 2 MEDIUM, 3 LOW

    Other records, highest priority first

    • TI-2026-71169 SQL injection in LibreNMS notifications lets users read password hashesPriority MEDIUM 64
    • TI-2026-71168 Stored cross-site scripting in LibreNMS wireless sensor descriptionsPriority MEDIUM 57
    • TI-2026-71170 Path traversal in LibreNMS lets users read unauthorized RRD dataPriority LOW 24
    Show all 6 records →

Timeline

  1. 2026-10-12 Threatist record created from CVE-2026-109357
  2. 2026-10-12 Alias added: GHSA-rx4g-rhf6-xw5x
  3. 2026-10-15 CISA SSVC decision points changed
  4. 2026-10-15 Priority changed: MEDIUM → HIGH

References

Advisory 1

  • TI-2018-14479 LibreNMS 1.46 allows remote attackers to execute arbitrary OS commands by using the… CVSS 3.0CRITICAL 9.8
  • TI-2026-59134 LibreNMS before 26.8.0 Authentication Bypass via API Token Type Confusion CVSS 4.0CRITICAL 9.2
  • TI-2026-57885 LibreNMS before 26.7.0 Stored XSS via Oxidized API CVSS 4.0CRITICAL 9.2
  • TI-2022-03735 Insufficient Session Expiration in librenms/librenms CVSS 3.1CRITICAL 9.8
  • TI-2026-57886 LibreNMS before 26.5.0 Remote Code Execution via AboutController CVSS 4.0HIGH 8.7
  • TI-2022-03252 Deserialization of Untrusted Data in librenms/librenms CVSS 3.1HIGH 8.8
See all 123 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences