Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2026-48558

SimpleHelp Authentication Bypass Authentication Bypass

SimpleHelp · affected before 5.5.16

Watch CVE-2026-48558 Browse KEV feed
Severity
CVSS 9.5 · Critical
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
5.7%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-48558 is an unauthenticated vulnerability affecting SimpleHelp. SimpleHelp versions 5.5.15 and prior and 6.0 pre-release versions contain an authentication bypass vulnerability in the OIDC authentication...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.

Who is affected?

SimpleHelp affected before 5.5.16.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

SimpleHelp Authentication Bypass Authentication Bypass

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.

SimpleHelp Affected
SimpleHelp
Before 5.5.16 Before 6.0 RC2
View vendor advisory (opens in new tab)
Published
12 Jun 2026
Exploitation Reported
29 Jun 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

cisa nuclei_scanner

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

BleepingComputer

Recorded 29 Jun 2026

A trusted third party reported exploitation.

Proof of concept available

GitHub

Recorded 02 Jul 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CISA First 2026-06-29 00:00 UTC
BleepingComputer 2026-06-29 14:20 UTC
CVE 2026-06-29 20:20 UTC
All CISA Advisories 2026-06-29 21:20 UTC
The Hacker News 2026-06-30 12:20 UTC
Rapid7 2026-09-11 13:35 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-48558.yaml 12 Sep 2026

Risk and context

Severity, weaknesses, and research context

CVSS v4.0

9.5 Critical

Potential damage if exploited. Separate from whether attackers are using it.

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

5.7%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Verification of Cryptographic Signature CWE-347

Recent mention · Rapid7

Metasploit Wrap Up: This One Goes to Sixteen!

This One Goes to Sixteen!Another banger from Metasploit with sixteen new modules, including ten exploit modules, with five on the CISA KEV list. Cisco, Papercut, Sonicwall, Jetbrains, and Langflow all have exploit modules, and not to be outdone, we even have a Metasploit...

Read full advisory

All CVSS Scores

CVSS v4.0 9.5 Critical

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

CVSS v3.1 10.0 Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

All Mentions

Recent mention · Rapid7

Metasploit Wrap Up: This One Goes to Sixteen!

Rapid7 · 11 Sep 2026

This One Goes to Sixteen!Another banger from Metasploit with sixteen new modules, including ten exploit modules, with five on the CISA KEV list. Cisco, Papercut, Sonicwall, Jetbrains, and Langflow all have exploit modules, and not to be outdone, we even have a Metasploit scanner to watch the watchers!New module content (16)Elasticsearch ingest-attachment Apache Tika XFA XXE Local File ReadAuthors: Bourbon Offensive Security Services and Jean-Marie BourbonType: AuxiliaryPull request: #21739 contributed by kmkzPath: scanner/http/elasticsearch_tika_xfa_xxeCVE...

Recent mention · The Hacker News

Attackers Exploit SimpleHelp CVE-2026-48558 to Deploy TaskWeaver and Djinn Stealer

The Hacker News · 30 Jun 2026

An unknown threat actor has been observed exploiting a recently disclosed maximum-severity security flaw in SimpleHelp to deliver two previously unreported malware families, TaskWeaver and Djinn Stealer. The intrusion involves the exploitation of CVE-2026-48558 (CVSS score: 10.0), a critical authentication bypass vulnerability impacting the OpenID Connect (OIDC) flow that an unauthenticated

Recent mention · Dark Reading

'Djinn' Stealer Targets Cloud, AI Credentials

Dark Reading · 29 Jun 2026

The infostealer was delivered via CVE-2026-48558, a critical authentication bypass vulnerability in SimpleHelp, targeting credentials linking development and admin environments to wider enterprise systems.

Recent mention · BleepingComputer

Critical SimpleHelp flaw exploited to deploy new stealer malware

BleepingComputer · 29 Jun 2026

Hackers are exploiting a recently disclosed critical vulnerability (CVE-2026-48558) in SimpleHelp to deploy Djinn Stealer, a previously undocumented cross-platform information stealer targeting Windows, macOS, and Linux. [...]

Recent mention · All CISA Advisories

CISA Adds One Known Exploited Vulnerability to Catalog

All CISA Advisories · 29 Jun 2026

CISA has added one new vulnerability to its Known Exploited Vulnerabilities (KEV) Catalog, based on evidence of active exploitation. CVE-2026-48558 SimpleHelp Authentication Bypass Vulnerability This type of vulnerability is a frequent attack vector for malicious cyber actors and poses significant risks to the federal enterprise. Binding Operational Directive (BOD) 26-04: Prioritizing Security Updates Based on Risk establishes vulnerability management requirements for Federal Civilian Executive Branch (FCEB) agencies. BOD 26-04 reinforces the importance of the KEV Catalog and requires...

Recent mention · Horizon3.ai Attack Research

CVE-2026-48558: SimpleHelp Authentication Bypass Indicators of Compromise

Horizon3.ai Attack Research · 12 Jun 2026

Horizon3.ai details indicators of compromise, affected configurations, and mitigation guidance for CVE-2026-48558, a SimpleHelp OIDC authentication bypass vulnerability.

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

CVE Record exploit — horizon3.ai

cve · Created Unknown

SimpleHelp <=5.5.15 - OIDC JWT Authentication Bypass

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. 04:30 UTC

    Public PoC available

    Public proof-of-concept code published

  2. 04:30 UTC

    Nuclei template available

    Scanner coverage available

  3. 13:35 UTC

    KEV confirmed by Rapid7

    Exploitation attested by an external source

  4. 12:20 UTC

    KEV confirmed by The Hacker News

    Exploitation attested by an external source

  5. 21:20 UTC

    KEV confirmed by All CISA Advisories

    Exploitation attested by an external source

  6. 20:20 UTC

    KEV confirmed by CVE

    Exploitation attested by an external source

  7. 14:20 UTC

    KEV confirmed by BleepingComputer

    Exploitation attested by an external source

  8. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  9. 17:07 UTC

    CVE published

    Vulnerability disclosed publicly

  10. 18:34 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-48558

Sample API response 
{
  "cve_id": "CVE-2026-48558",
  "confidence": "Confirmed",
  "cvss_score": 9.5,
  "cvss_estimated": false,
  "epss_score": 0.05719,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}