What is CVE-2026-48558?
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.
The record classifies CVE-2026-48558 under weakness class CWE-347. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 145 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 10 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - CVSS v4.0 base score
- 9.5
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - EPSS (FIRST)
- 0.7% probability of exploitation in the next 30 days, higher than 49.2% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-06-12, last modified 2026-06-13
Is CVE-2026-48558 being exploited?
It currently carries a trending score of 44 in the Threadlinqs vulnerability feed.
Affected products and versions
- SimpleHelp: SimpleHelp
How to fix CVE-2026-48558
No vendor patch reference has been recorded for CVE-2026-48558 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-48558
3 tracked threats in the Threadlinqs corpus reference CVE-2026-48558, either in the campaign’s CVE list or as an indicator on the campaign record.
- CitrixBleed 2 (CVE-2025-5777) Exploited by Anubis Ransomware Affiliates Alongside Valid VPN Credentials and RMM Tool Abuse — CRITICAL · 2026-10-27
- SimpleHelp Authentication Bypass via Forged OIDC Tokens (CVE-2026-48558) Actively Exploited, Added to CISA KEV — CRITICAL · 2026-07-05
- SimpleHelp RMM OIDC Authentication Bypass (CVE-2026-48558) — Unauthenticated Forged-Token Technician Account Creation and MFA Bypass — CRITICAL · 2026-06-16
Sources
Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.