SimpleHelp Authentication Bypass Vulnerability
SimpleHelp — SimpleHelp
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.
10.0
30.0%
Vector breakdown
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Published
- Jun 12, 2026
- Modified
- Oct 7, 2026
- Added to KEV
- Jun 29, 2026
- Federal patch due
- Jul 2, 2026
CISA required action
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.
Weakness classification
Affected packages
Proof-of-concept & exploitation references
1 foundWeaponization
Public repositories whose name or description references CVE-2026-48558, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
References
How this class of flaw gets exploited
Frequently asked questions
What is CVE-2026-48558?
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.
How severe is CVE-2026-48558?
CVE-2026-48558 has a CVSS base score of 10.0 out of 10 (CVSS 3.1).
Is CVE-2026-48558 actively exploited in the wild?
Yes. CVE-2026-48558 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Jun 29, 2026, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2026-48558?
30.0% - meaning FIRST.org's EPSS model estimates a 30.0% probability this vulnerability will be exploited in the wild within 30 days (98% percentile among all scored CVEs).
Is there exploit tooling available for CVE-2026-48558?
Yes - a public Nuclei template referencing CVE-2026-48558 exist in public repositories we checked. We also found 1 public GitHub repositories referencing this CVE.
What type of vulnerability is CVE-2026-48558?
CVE-2026-48558 is classified under CWE-347 (Improper Verification of Cryptographic Signature).
Cross-checked against
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