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
Proof-of-concept & exploitation references
Weaponization
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.
No public GitHub repositories referencing CVE-2026-48558 were found at last check. Absence here is not proof no exploit exists — see the references below for vendor advisories and write-ups.
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.
What type of vulnerability is CVE-2026-48558?
CVE-2026-48558 is classified under CWE-347 (Improper Verification of Cryptographic Signature).
Cross-checked against
Impactr finds and proves whether CVE-2026-48558 — or flaws like it — are actually reachable in your own web apps and APIs, with a reproducible exploit as evidence.