CVE-2026-48558
SimpleHelp Authentication Bypass via Missing OIDC JWT Signature Verification
- Critical 10.0
- Exploited: added to CISA KEV 29 Jun 2026
- A public exploit reference is listed
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.
Key facts
- Published
- 12 Jun 2026
- Last changed
- 7 Oct 2026
- Assigned by
- VulnCheck
- KEV added
- 29 Jun 2026
- KEV fix due
- 2 Jul 2026
- EPSS
- 80.251% likely to be exploited in the next 30 days, higher than 99.625% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: yes; Technical impact: total
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 9.5CVSS 4.0, Criticalfrom the CNA (VulnCheck)
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 - 10.0CVSS 3.1, Criticalfrom the CNA (VulnCheck)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
What to do
- 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.CISA KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| SimpleHelp | SimpleHelp |
|
Timeline
- 12 Jun 2026 Published
- 29 Jun 2026 Added to the CISA KEV catalogue