CVE-2026-48558

CRITICAL CISA KEV EPSS 49.3%
Published Jun 12, 20262w ago · Modified Jun 17, 20261w ago
9.5 CVSS 4.0
Critical
Find Similar
Published Jun 12, 2026 2w ago
Last Modified Jun 17, 2026 1w ago
KEV Listed Jun 29, 2026 2d ago
KEV Due Jul 2, 2026 1d remaining

Description

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.

CVSS Details

Base Score
9.5
Exploitability
Impact
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

CISA Known Exploited 1d to due date
Added
Jun 29, 2026
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.

EPSS Exploit Probability
49.3% percentile
Exploit & Patch Status
Actively Exploited (KEV)
No Patch Available

Weaknesses 1

CWE-347

References 3

  • 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

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.