Critical 9.2Published Sep 7, 2026

CVE-2026-86426LibreNMS before 26.8.0 Authentication Bypass via API Token Type Confusion

Updated under an hour ago (2026-10-19 07:30 UTC)

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It affects librenms. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 9.2 CRITICAL (v4.0, CNA)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
Weakness (CWE): CWE-287
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Analyzed
Record last updated: Sep 8, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

librenms librenms librenms:librenms (from the name)	before 26.8.0; 26.8.0 not affected	CNA record
librenms librenms librenms:librenms	before 26.8.0	NVD

References

https://github.com/librenms/librenms/security/advisories/GHSA-cvq8-gqfq-3mvgvendor-advisory, exploit
https://www.vulncheck.com/advisories/librenms-before-26.8.0-authentication-bypass-via-api-token-type-confusionthird-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.