LibreNMS up to 26.8.x LDAP Authorization PHP_AUTH_USER injection

CVSS Meta Temp Score
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CTI Interest Score
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7.5$0-$5k1.22

Summaryinfo

A vulnerability has been found in LibreNMS up to 26.8.x and classified as critical. Affected by this issue is some unknown functionality of the component LDAP Authorization. The manipulation of the argument PHP_AUTH_USER leads to injection. This vulnerability is uniquely identified as CVE-2026-109357. The attack is possible to be carried out remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in LibreNMS up to 26.8.x. It has been rated as critical. This issue affects an unknown part of the component LDAP Authorization. The manipulation of the argument PHP_AUTH_USER with an unknown input leads to a injection vulnerability. Using CWE to declare the problem leads to CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-109357 since 10/12/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1055 for this issue.

Upgrading to version 26.9.0 eliminates this vulnerability.

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Productinfo

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.7
VulDB Meta Temp Score: 7.5

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.1
CNA Vector (VulnCheck): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Injection
CWE: CWE-74 / CWE-707 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: LibreNMS 26.9.0

Timelineinfo

10/12/2026 Advisory disclosed
10/12/2026 +0 days CVE reserved
10/12/2026 +0 days VulDB entry created
10/12/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-109357 (🔒)
GCVE (CVE): GCVE-0-2026-109357
GCVE (VulDB): GCVE-100-417077

Entryinfo

Created: 10/12/2026 19:39
Changes: 10/12/2026 19:39 (76)
Complete: 🔍
Cache ID: 216::103

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