Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-86426

CVE-2026-86426CRITICAL

LibreNMS before 26.8.0 Authentication Bypass via API Token Type Confusion

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   N   L   P   N   N   H   H   H    9.2   .0387   89.9     —

AFFECTED
  Product   Versions     Fixed
  librenms  unspecified  26.8.0

TIMELINE
  Sep 7   Reserved by VulnCheck
  Sep 7   Published (CNA: VulnCheck)
  Sep 18  EXPLOIT PUBLISHED — CVE-2026-86426 (librenms). Public exploit reference added.

CWE-287 · CNA: VulnCheck · CVSS v4.0 · 2 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
September 7, 2026	Reserved	Reserved by VulnCheck
September 7, 2026	Published	Published (CNA: VulnCheck)
September 18, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-86426 (librenms). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
librenms	librenms	—	—	26.8.0

Weaknesses

CWE-287

References (2)

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]

Authoritative record: CVE-2026-86426 at cve.org

Vendors: librenms

Weaknesses: CWE-287

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-86426 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.