All vulnerabilities
CVE-2026-86426GHSA-cvq8-gqfq-3mvg

LibreNMS before 26.8.0 Authentication Bypass via API Token Type Confusion

librenms librenms
Open in ThreatlineRecord JSON
CVSS
9.2Critical
ExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 8 Sep 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)3.87%Chance of exploitation activity in the next 30 days, higher than 90% of CVEs. Scored 24 Oct 2026FIRST EPSS
Fixed in26.8.0Fixed versionCVE List
Published7 Sep 2026Updated 9 Sep 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 7 Sep 2026, 12:53 UTCPublishedCVE List
  2. 25 Oct 2026, 04:54 UTCExploit code publicGitHub proof-of-concept repositories

Public exploit code and templates 1

  • Scanner templateLibreNMS <= 26.7.0 - Unauthenticated API AccessNuclei

Listed so defenders can prioritize. Threatline links to the source and does not host exploit code.

Reports 1

1 outlet mention it. Reports are not confirmation; each links to its source.

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.

Text from CVE List

Affected versions 3

  • librenmsaffected: all versions before 26.8.0CVE List
  • librenmsunaffected: 26.8.0CVE List
  • LibreNMS<= 26.7.0GitHub

References 2