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.
Is CVE-2026-48558 exploited?
Listed in the CISA KEV catalog on 2026-06-29.
Federal remediation due 2026-07-02.
Past that date by 44 days.
EPSS puts exploitation in the next 30 days at 11%.
Public exploit code: none found in monitored sources.