Exploited vulnerability · CISA KEV

Is CVE-2026-48558 exploited? Yes: in CISA KEV since 29 Jun 2026

Gociux · SimpleHelp · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2026-48558, SimpleHelp Authentication Bypass Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 29 Jun 2026, 17 days after it was published. It affects SimpleHelp. If you run it, CISA's required action is: 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.

What it is

SimpleHelp contains 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.

What to do

1. Check whether you run it. Look for SimpleHelp in your asset inventory, including appliances and cloud images. Stack check lists every exploited SimpleHelp CVE at once.
2. Apply the fix. 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.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 12 Jun 2026.
4. Get told next time. Email alerts when CISA adds a CVE for SimpleHelp.

Other exploited CVEs in SimpleHelp

• CVE-2024-57728: SimpleHelp Path Traversal Vulnerability (24 Apr 2026)
• CVE-2024-57726: SimpleHelp Missing Authorization Vulnerability (24 Apr 2026)
• CVE-2024-57727: SimpleHelp Path Traversal Vulnerability (13 Feb 2025)

References

• simple-help.com/security/simplehelp-security-update-2026-05
• nvd.nist.gov/vuln/detail/CVE-2026-48558

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in June 2026 · SimpleHelp scorecard · act-now radar.