# CVE-2026-48558: SimpleHelp Authentication Bypass via Missing OIDC JWT Signature Verification

> CVE-2026-48558: SimpleHelp Authentication Bypass via Missing OIDC JWT Signature Verification. CVSS 10.0 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2026-48558
Last updated: 2026-10-07T20:17:12Z

- Published: 2026-06-12 17:07 UTC · Updated: 2026-10-07 20:17 UTC · Assigner: VulnCheck
- CVSS: 10.0 (CVSS 3.1) · Severity: Critical · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- EPSS: 77.7%, 100th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2026-06-29, federal due date 2026-07-02, ransomware use: Unknown
- CWE: CWE-347

## 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.

## CISA 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 vendors and products

- SimpleHelp: SimpleHelp

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-48558)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-48558)
- [https://horizon3.ai/attack-research/disclosures/cve-2026-48558-simplehelp-authentication-bypass-iocs/](https://horizon3.ai/attack-research/disclosures/cve-2026-48558-simplehelp-authentication-bypass-iocs/)
- [https://simple-help.com/release-news](https://simple-help.com/release-news)
- [https://simple-help.com/security/simplehelp-security-update-2026-05](https://simple-help.com/security/simplehelp-security-update-2026-05)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-48558 · Markdown: https://rewindex.com/cve/CVE-2026-48558.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-48558 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:01:37.068Z