---
id: CVE-2026-86426
title: >-
  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
summary: >-
  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 ty…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-287
vendor: librenms
product: librenms
affected:
  - librenms < 26.8.0
patched:
  - librenms 26.8.0
published: '2026-09-07'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:37:30.103'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-86426'
references:
  - url: >-
      https://github.com/librenms/librenms/security/advisories/GHSA-cvq8-gqfq-3mvg
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/librenms-before-26.8.0-authentication-bypass-via-api-token-type-confusion
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/librenms/librenms/security/advisories/GHSA-cvq8-gqfq-3mvg
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - exploit-available
  - cve.org
epss: 0.0387
epssPercentile: 0.89809
exploits:
  nuclei:
    - CVE-2026-86426
  checkedAt: '2026-09-26T09:06:03.479Z'
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-08T13:38:14.229547Z'
scores:
  nvd: 9.8
  cna: 9.2
ingestedAt: '2026-09-08T15:33:26.977Z'
---

## Overview

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.

## Affected

- `librenms < 26.8.0`

## Remediation

Upgrade past the affected range:

- `librenms 26.8.0`