CVE-2026-48558KEV · OVERDUECWE-347

SimpleHelp Authentication Bypass Vulnerability

Critical · published June 12, 2026

Patch now

Confirmed exploited, and the score agrees

CVSS calls it critical at 10.0. It is confirmed in active exploitation. It sits in the 93.0th percentile for exploit probability.

113
days past CISA
deadline
CVSS v3.1
10.0
EPSS
6%
Percentile
93.0
In the wild
Confirmed
What it is

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
Technical detail
CVSS v3.1
10.0 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.05719 · 93.0th percentile
Weakness
CWE-347 · Improper Verification of Cryptographic Signature
Published
2026-06-12T22:16Z
KEV added
2026-06-29 · due 2026-07-02
Affected products (2)
ProductVersionsFixed in
simple-help/simplehelp< 5.5.165.5.16
simple-help/simplehelpall versions—
References (5)
EPSS history
Timeline
  • 25 SEP 03:26Z
    EPSS moved 64% → 6%
    epss
  • 13 SEP 03:22Z
    EPSS moved 30% → 64%
    epss
  • 12 SEP 03:21Z
    EPSS moved 30% → 64%
    epss
  • 04 SEP 03:41Z
    EPSS moved 12% → 30%
    epss
  • 03 SEP 03:30Z
    EPSS moved 12% → 30%
    epss
  • 29 JUN 00:00Z
    Added to CISA KEV — remediate by Jul 2
    kev
  • 12 JUN 17:07Z
    SimpleHelp Authentication Bypass via Missing OIDC JWT Signature Verification
    cvelistv5