CVE-2026-48558
CriticalExploitedPublic exploitSimpleHelp versions 5.5.15 and prior and 6.0 pre-release versions contain an authentication bypass vulnerability in the OIDC authentication flow.
Published Jun 12, 2026 · Updated Oct 7, 2026
Key Facts
Patch immediately- CVE-2026-48558 is a critical-severity vulnerability (CVSS 9.5 v4) affecting SimpleHelp (Simple-Help).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jun 29, 2026. Public exploit code is available.
- EPSS estimates a 5.7% probability of exploitation in the next 30 days.
- Fixed versions are available, including SimpleHelp 5.5.16, SimpleHelp 6.0 rc2.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v4
9.5
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
EPSS (30-day exploit likelihood)
5.7%
Higher than 92.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-48558 brief as a PDF
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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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Jun 29, 2026 | Jul 2, 2026 | Not reported |
| Industry KEV feed | Jun 29, 2026 | Jul 2, 2026 | Not reported |
| CIRCL KEV | Jun 29, 2026 | Jul 2, 2026 | Not reported |
| ENISA EUVD | Jun 29, 2026 | n/a | Not reported |
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.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| SimpleHelpSimple-Help | 6.0-pre-release, >= 5.5.0 | 5.5.16 |
Patched Releases
SimpleHelp
5.5.16, 6.0 rc2, 6.0 RC2
Timeline
Publicly disclosed
Jun 12, 2026
Added to CISA KEV
Jun 29, 2026
Added to Industry KEV feed
Jun 29, 2026
Added to CIRCL KEV
Jun 29, 2026
Added to ENISA EUVD
Jun 29, 2026
Last updated
Oct 7, 2026
Weakness Type
- CWE-347 Improper Verification of Cryptographic Signature
References
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitMSF simplehelp_oidc_auth_bypass_rce.rb
- exploitVulnCheck exploitation report
FAQ
Common Questions.
SimpleHelp versions 5.5.15 and prior and 6.0 pre-release versions contain an authentication bypass vulnerability in the OIDC authentication flow.
Affected: SimpleHelp (Simple-Help) versions 6.0-pre-release, >= 5.5.0. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Jun 29, 2026.
Yes. It was added on Jun 29, 2026 with a federal remediation due date of Jul 2, 2026.
Public exploit code is available.
Fixed versions are available, including SimpleHelp 5.5.16, SimpleHelp 6.0 rc2.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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