CVE-2026-86426CWE-287

CVE-2026-86426

Critical · published September 7, 2026

CVSS v3.1
9.8
EPSS
4%
Percentile
90.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
9.2 · 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
EPSS
0.03870 · 90.1th percentile
Weakness
CWE-287 · Improper Authentication
Published
2026-09-07T17:20Z
Affected products (1)
ProductVersionsFixed in
librenms/librenms< 26.8.026.8.0
References (3)
https://github.com/librenms/librenms/security/advisories/GHSA-cvq8-gqfq-3mvg · [email protected]https://www.vulncheck.com/advisories/librenms-before-26.8.0-authentication-bypass-via-api-token-type-confusion · [email protected]https://github.com/librenms/librenms/security/advisories/GHSA-cvq8-gqfq-3mvg · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 09 SEP 03:20Z
    EPSS moved — → 1%
    epss
  • 07 SEP 12:53Z
    LibreNMS before 26.8.0 Authentication Bypass via API Token Type Confusion
    cvelistv5