by Kastro
Paper/Archive/CVE-2026-109357

CVE-2026-109357

librenms librenms — LibreNMS before 26.9.0 LDAP Filter Injection Authentication Bypass via Authorization Header

EPSS 0.6%public exploitCVSS 9.2
critical.is priorityof 100
47
CVSS 9.2 (CNA)9.2 / 10 × 3027.6Not in CISA KEV+300.0EPSS percentile 48.4.484 × 209.7Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
librenms< 26.9.026.9.0CNA

Scores by source

VulnCheck (CNA)9.2CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
VulnCheck (CNA)8.1CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: total

References

exploitgithub.com/librenms/librenms/security/advisories/GHSA-7cmx-65c5-8h8vwriteupvulncheck.com/advisories/librenms-before-26.9.0-ldap-filter-injection-authentication-bypass-via-authorization-header