CVE-2026-86426

LibreNMS before 26.8.0 Authentication Bypass via API Token Type Confusion

Published Sep 7, 2026 CVSS 4.0 · 9.2 Critical EPSS 4.4% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title LibreNMS before 26.8.0 Authentication Bypass via API Token Type Confusion
First Time appeared Librenms
Librenms librenms
Weaknesses CWE-287
CPEs cpe:2.3:a:librenms:librenms:*:*:*:*:*:*:*:*
Vendors & Products Librenms
Librenms librenms
References
Metrics cvssV4_0

{'score': 9.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 8, 2026, 1:39 PM
Reserved
Sep 7, 2026, 12:33 PM
Status
Analyzed
Published
Sep 7, 2026, 1:20 PM
Modified
Sep 18, 2026, 6:37 PM