CVE-2026-48558: SimpleHelp Authentication Bypass Vulnerability
Affects SimpleHelp SimpleHelpSource CISA KEV
Exploited in the wild · KEV due 2 Jul 2026 · public exploit available (Metasploit) · 5% EPSS : apply the vendor's fix or mitigations to SimpleHelp SimpleHelp now.
Data as of 10/24/2026, 22:16:03 UTC
- Exploitation
Actively exploited – in CISA KEV since 06/29/2026
- KEV deadline
- 07/02/2026 US federal agencies must patch by this date; a sensible deadline for everyone else.
- EPSS
- 5.7% chance of exploitation in 30 days – higher than 93% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Public exploits
- 1 Metasploit module, a Nuclei detection templatePublic attack or detection tooling exists; see Public exploits below.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:HWhat to do
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.
- simple-help.com/security/simplehelp-security-update-2026-05 (opens in a new tab)
- cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (opens in a new tab)
- cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-48558 (opens in a new tab)
Public exploits and detection
Metasploit modules
Nuclei detection templates
Public tooling indexed from Metasploit Framework, Exploit-DB and ProjectDiscovery nuclei-templates. Its existence raises the odds of exploitation; it does not confirm attacks.
Description
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.
Weaknesses
- CWE-347Improper Verification of Cryptographic Signature (opens in a new tab)
Base weaknessOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
References
- simple-help.com/security/simplehelp-security-update-2026-05 (opens in a new tab)
- cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (opens in a new tab)
- cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-48558 (opens in a new tab)
- cisa.gov/known-exploited-vulnerabilities-catalog?search=CVE-2026-48558 (opens in a new tab)