CVE-2026-48558: SimpleHelp Authentication Bypass Vulnerability

Critical severity, CVSS 10.0. Actively exploited: in CISA KEV since 2026-06-29. EPSS: 5.7% chance of exploitation in the next 30 days.

SimpleHelp versions 5.5.15 and prior and 6.0 pre-release versions contain an authentication bypass vulnerability in the OIDC authentication flow. When OIDC authentication is configured, identity tokens submitted during login are accepted without verifying their cryptographic signature. In a vulnerable configuration, a remote, unauthenticated attacker can submit a forged token containing arbitrary identity claims to obtain a fully authenticated technician session. In some configurations, this may also allow bypass of multi-factor authentication. No user interaction is required.

Affected products

• SimpleHelp SimpleHelp: before 5.5.16 (fixed in 5.5.16); version 6.0 only

Published 2026-06-12. Last modified 2026-10-07.