SimpleHelp Authentication Bypass Vulnerability
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.
Quick answer
SimpleHelp should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- 6.0
Fixed versions
- Apply the latest vendor-supported patched version.
How to fix it
SimpleHelp is affected by an OIDC authentication bypass where identity token signatures may not be verified in vulnerable configurations. Upgrade to the SimpleHelp security update, review OIDC configuration, and rotate technician and integration credentials. Because the issue can create authenticated technician sessions, inspect remote access activity carefully.
- Inventory SimpleHelp servers and identify deployments with OIDC authentication enabled.
- Upgrade SimpleHelp to the fixed release from the vendor security update for CVE-2026-48558.
- Verify OIDC token signature validation, issuer, audience, expiration, and MFA enforcement are configured correctly.
- Restrict technician portal and administration access to trusted networks and SSO-protected users.
- Review technician sessions, remote support history, audit logs, user creation, and configuration changes for forged-token activity.
- Rotate SimpleHelp administrator credentials, OIDC client secrets, technician credentials, and API or integration tokens if exposure is suspected.
- Disable OIDC temporarily or limit access if the fixed release cannot be applied immediately.
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Verify the fix
- Confirm the SimpleHelp version is fixed for CVE-2026-48558.
- Validate forged or unsigned OIDC tokens are rejected during login testing.
- Review remote support session logs for unauthorized technician sessions or MFA bypass.
- Test normal OIDC login and technician workflows after applying the update.
- Run a Fixnx scan and confirm no public SimpleHelp admin exposure remains.
Related categories
Trusted references
FAQ
What is affected by CVE-2026-48558?
SimpleHelp versions listed as affected should be reviewed: 6.0.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
Why can this risk appear in multiple categories?
A vulnerability can belong to more than one platform or ecosystem. Fixnx keeps one canonical risk page while also listing it in every relevant category.