CVE-2026-48558SimpleHelp Authentication Bypass via Missing OIDC JWT Signature Verification
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.
Overview
Severity
| Score | Severity | Version | Vector String |
|---|---|---|---|
| 9.5 | CRITICAL | 4.0VulnCheck (CNA) | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H |
| 10.0 | CRITICAL | 3.1VulnCheck (CNA) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
CISA required action
⚡ Known exploited · remediation due Jul 2, 2026
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Details
- CVE ID
- CVE-2026-48558
- Status
- Analyzed
- Assigner (CNA)
- VulnCheck
- Published
- Jun 12, 2026
- Last modified
- 2026-10-07 20:17 UTC
- Weaknesses
- CWE-347 · Improper Verification of Cryptographic Signature
Affected Products
As published by the CNA in the CVE record.
SimpleHelpSimpleHelp2 version ranges
- 5.5.0 before 5.5.16
- 6.0 before 6.0 RC2
References
- horizon3.ai https://horizon3.ai/attack-research/disclosures/cve-2026-48558-simplehelp-authentication-bypass-iocs/
- simple-help.com https://simple-help.com/release-news
- simple-help.com https://simple-help.com/security/simplehelp-security-update-2026-05
- blackpointcyber.com https://blackpointcyber.com/blog/a-djinn-in-the-machine-taskweavers-node-js-intrusion-chain/
- cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-48558