CVE-2026-86426 PUBLISHED

LibreNMS before 26.8.0 Authentication Bypass via API Token Type Confusion

Assigner: VulnCheck
Reserved: 07.09.2026 Published: 07.09.2026 Updated: 07.09.2026

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.

Metrics

CVSS Vector: 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
CVSS Score: 9.2

Product Status

Vendor librenms
Product librenms
Versions Default: unaffected
  • affected from 0 to 26.8.0 (excl.)
  • Version 26.8.0 is unaffected

Credits

  • rbs-astsec reporter

References

Problem Types

  • Improper Authentication CWE