CVE-2026-86426

LibreNMS before 26.8.0 contains an authentication bypass vulnerability in the REST API that allows unauthenticated attackers to access protected endpoints by sending numeric values instead of string tokens. Attackers can exploit MySQL type coercion by sending small integers like 0 through 9 to match token hashes, gaining access to API functionality including device credentials and administrative features that enable remote code execution through alert templates.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/librenms/librenms/security/advisories/GHSA-cvq8-gqfq-3mvg	Exploit Vendor Advisory
https://www.vulncheck.com/advisories/librenms-before-26.8.0-authentication-bypass-via-api-token-type-confusion	Third Party Advisory
https://github.com/librenms/librenms/security/advisories/GHSA-cvq8-gqfq-3mvg	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:librenms:librenms:*:*:*:*:*:*:*:*

History

18 Sep 2026, 18:37

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 9.8
CPE		cpe:2.3:a:librenms:librenms::::::::
First Time		Librenms Librenms librenms
References	~~() https://github.com/librenms/librenms/security/advisories/GHSA-cvq8-gqfq-3mvg -~~	() https://github.com/librenms/librenms/security/advisories/GHSA-cvq8-gqfq-3mvg - Exploit, Vendor Advisory
References	~~() https://www.vulncheck.com/advisories/librenms-before-26.8.0-authentication-bypass-via-api-token-type-confusion -~~	() https://www.vulncheck.com/advisories/librenms-before-26.8.0-authentication-bypass-via-api-token-type-confusion - Third Party Advisory

Information

Published : 2026-09-07 13:20

Updated : 2026-09-18 18:37

NVD link : CVE-2026-86426

Mitre link : CVE-2026-86426

CVE.ORG link : CVE-2026-86426

JSON object : View

Products Affected

librenms

librenms

CWE

CWE-287

Improper Authentication

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