SimpleHelp 5.5.x < 5.5.16 OIDC Authentication Bypass

critical Nessus Plugin ID 333310

Synopsis

The SimpleHelp instance running on the remote host is affected by an authentication bypass vulnerability.

Description

The version of SimpleHelp running on the remote web server is 5.5.x prior to 5.5.16 (or a 6.0 pre-release prior to 6.0 RC2). It is, therefore, affected by 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, allowing privileged management activities such as remoting into managed endpoints and executing scripts. In some configurations this may also allow a bypass of multi-factor authentication. No user interaction is required.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to SimpleHelp version 5.5.16 / 6.0 RC2 or later to address this issue.

See Also

https://simple-help.com/security/simplehelp-security-update-2026-05

http://www.nessus.org/u?3ee1e313

http://www.nessus.org/u?d22b78d0

Plugin Details

Severity: Critical

ID: 333310

File Name: simplehelp_cve-2026-48558.nasl

Version: 1.1

Type: Remote

Family: Web Servers

Published: 8/7/2026

Updated: 8/7/2026

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 9.3

Percentile: 99.81

CVSS v2

Risk Factor: Critical

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-48558

CVSS v3

Risk Factor: Critical

Base Score: 10

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Vulnerability Information

CPE: x-cpe:/a:simplehelp:simplehelp

Required KB Items: installed_sw/SimpleHelp, Settings/ParanoidReport

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/9/2026

Vulnerability Publication Date: 6/12/2026

CISA Known Exploited Vulnerability Due Dates: 6/29/2026

Reference Information

CVE: CVE-2026-48558