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LibreNMS before 26.8.0 contains an authentication bypass vulnerability in the REST API that allows unauthenticated attackers to access protected… (CVE-2026-86426)

0
Critical
Published: 09/07/2026 (09/07/2026, 15:33:53 UTC)
Source: GCVE Database

Description

LibreNMS versions before 26.8.0 have an authentication bypass vulnerability in the REST API. This flaw allows unauthenticated attackers to access protected API endpoints by exploiting MySQL type coercion with numeric values instead of string tokens. Successful exploitation can expose device credentials and administrative features, potentially enabling remote code execution via alert templates.

CVSS v3.1

Score 9.8critical

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected software

Affected versions
<26.8.0

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 09/19/2026, 01:34:26 UTC

Technical Analysis

CVE-2026-86426 describes an authentication bypass vulnerability in LibreNMS prior to version 26.8.0. The REST API improperly handles authentication tokens by allowing numeric values (0-9) to bypass token validation due to MySQL type coercion. This enables unauthenticated attackers to access protected API endpoints, including those that expose sensitive device credentials and administrative functions. The administrative features accessible through this bypass can be leveraged to execute remote code via alert templates, posing a critical security risk.

Potential Impact

The vulnerability allows unauthenticated attackers to bypass authentication controls in the LibreNMS REST API, leading to unauthorized access to sensitive device credentials and administrative functions. This can result in full system compromise through remote code execution, severely impacting confidentiality, integrity, and availability of the affected system.

Mitigation Recommendations

A fix is available in LibreNMS version 26.8.0. Users should upgrade to version 26.8.0 or later to remediate this vulnerability. No other mitigation guidance is provided in the available data.

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Technical Details

Gcve Source
db.gcve.eu
Osv Id
GHSA-84cr-xjpw-q9mc
Osv Schema Version
1.4.0
Aliases
["CVE-2026-86426"]
Database Specific Severity
CRITICAL
Cvss Version
3.1

Threat ID: 6aade4ea55bf5e2cf5ed9f0e

Added to database: 09/19/2026, 01:27:06 UTC

Last enriched: 09/19/2026, 01:34:26 UTC

Last updated: 09/19/2026, 02:01:10 UTC

Views: 3

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