Actively exploited KEV catalog No authentication
CVE-2026-48558

SimpleHelp Authentication Bypass Vulnerability

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…

CheckOps priority index
8.5/10 Patch within 24 h
Severity9.5
Probability7.8
Exploitation4/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 77.7% higher than 99.6% of CVEs
CVSS 4.0 9.5 AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/
Exploited for 127 days 29 Jun 2026
CISA due date 02 Jul 2026 for US federal agencies

Exploitation probability EPSS · FIRST

05010025 Sep05 Oct15 Oct24 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 4 / 5

  • KEV catalog (CISA)29 Jun 2026
  • Exploited in EUVD (ENISA)29 Jun 2026
  • Used by ransomwareno
  • EPSS above 10 %77.7%
  • No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: 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.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

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.

Affected products

SimplehelpSimpleHelp
Affected versions
  • 5.5.0 <5.5.16
  • 6.0 <6.0 RC2
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

  5. EPSS peak: 77.7%

References

Other exploited vulnerabilities from the same vendor

  • CVE-2024-57728SimpleHelp Path Traversal Vulnerability
    7.2 · Background exploitation
  • CVE-2024-57726SimpleHelp Missing Authorization Vulnerability
    8.4 · Background exploitation
  • CVE-2024-57727SimpleHelp Path Traversal Vulnerability
    9.5 · Background exploitation

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Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities