SimpleHelp Authentication Bypass via Forged OIDC Tokens (CVE-2026-48558) Actively Exploited, Added to CISA KEV

SimpleHelp Authentication Bypass via Forged OIDC Tokens (TL-2026-1122), also tracked as TaskWeaver/Djinn Stealer Campaign, is a critical-severity software vulnerability scored CVSS 10, first published 2026-07-05 and last reviewed 2026-07-11. It has no confirmed attribution, affects SimpleHelp SimpleHelp Remote Support / RMM Software, references 1 CVE (CVE-2026-48558), maps to 48 MITRE ATT&CK techniques (T1005, T1016, T1020), and is covered by 9 detection rules and 46 indicators of compromise.

Key facts for TL-2026-1122

Threat ID
TL-2026-1122
Also known as
TaskWeaver/Djinn Stealer Campaign
Severity
CRITICAL
CVSS
10 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H)
Status
ACTIVE
Category
VULNERABILITY
First published
2026-07-05
Last reviewed
2026-07-11
Attribution confidence
LOW
Motivation
FINANCIAL
Target sectors
technology, managedserviceproviders, softwaredevelopment, cross-sector
Target regions
Global, North America
Detection rules
9
Indicators of compromise
46
Updates
2026-07-11 · 5 updates · revalidated 5× · latest source

Malware and tooling in SimpleHelp Authentication Bypass via Forged OIDC Tokens

Malware and tooling: Djinn Stealer, TaskWeaver, Claude, Cline, Codex, Docker, Gemini, Helm, Kilo, OpenCode, SimpleHelp

CVE-2026-48558 is a maximum-severity (CVSS 10.0) authentication bypass in SimpleHelp remote support/RMM software configured with OpenID Connect (OIDC), caused by failure to verify the cryptographic signature of identity tokens (CWE-347). Unauthenticated attackers can submit a forged identity token with arbitrary claims to obtain a fully authenticated Technician session, in some configurations bypassing MFA entirely, and are actively using this access to deploy the novel TaskWeaver Node.js loader and Djinn Stealer infostealer against MSP-managed environments.

How SimpleHelp Authentication Bypass via Forged OIDC Tokens works

CVE-2026-48558 affects SimpleHelp deployments that have at least one OIDC identity provider configured, a Technician Group associated with that provider, and the "Allow group authenticated logins" setting enabled (including both generic OIDC and Azure AD OIDC configurations). In this configuration, SimpleHelp accepts identity tokens submitted during the OIDC login flow without verifying their cryptographic signature. A remote, unauthenticated attacker can therefore craft a forged identity/JWT-style token containing arbitrary identity claims and present it to the login endpoint to create and authenticate as a new, fully privileged "Technician" account. Because SimpleHelp allows technicians to self-register their own MFA method on first login, the forged-account path can also result in a full bypass of any configured multi-factor authentication.

Horizon3.ai's Zach Hanley, working through the firm's autonomous "Sua Sponte" AI-driven vulnerability research initiative, privately reported the flaw to SimpleHelp on 2026-05-22. SimpleHelp silently shipped fixed builds (5.5.16 and 6.0 RC2) around 2026-05-26, and Horizon3.ai publicly disclosed full technical detail and indicators of compromise on 2026-06-12. Internet-wide scanning at disclosure time found roughly 14,000 SimpleHelp servers exposed to the internet, of which approximately 7.2% (roughly 1,000 servers) were configured in the vulnerable OIDC/group-authentication mode.

On 2026-06-29, BlackPoint Cyber's Adversary Pursuit Group published "A Djinn in the Machine," documenting a real-world intrusion in which an attacker exploited CVE-2026-48558 against an internet-facing SimpleHelp server to obtain a forged Technician session, then abused the RMM's own remote file-transfer and remote-execution capabilities to push a malicious payload to managed endpoints. The payload was a 1.08 MB, single-line, heavily obfuscated Node.js file named "jquery.js" (to masquerade as the legitimate jQuery library), staged on a temporary Cloudflare Tunnel (trycloudflare.com) URL and executed via node.exe. This loader, dubbed TaskWeaver, fingerprints the host and establishes an encrypted, reusable command channel to a remote server at a.dev-tunnels[.]com, allowing the operator to push arbitrary follow-on JavaScript modules without modifying the loader itself.

TaskWeaver's primary observed payload is Djinn Stealer, a previously undocumented, cross-platform (Windows, macOS, Linux) information stealer that reuses TaskWeaver's obfuscation framework and embeds the identical RSA-2048 public key, tying the two families to the same operator. Djinn Stealer harvests cloud-provider credentials (AWS, Azure, Google Cloud, Oracle, Okta, Cloudflare), developer/DevOps credentials (GitHub, Git configuration, SSH private keys, Docker, Helm, npm, pip/PyPI, Cargo, Maven and other package-registry tokens), AI coding-assistant credentials (Claude, Gemini, Codex, Cline), cryptocurrency wallets (Bitcoin, Ethereum, Monero, Exodus, Atomic Wallet), browser-stored data, shell history, and PGP keys. On Linux hosts it additionally reads /proc/<pid>/cmdline and /proc/<pid>/environ to recover secrets embedded in running-process arguments and environment variables. Collected data is packed into a TAR archive, compressed with GZIP, and encrypted with AES-256-GCM using a key itself protected by an embedded RSA-2048 public key, before being exfiltrated to an attacker-controlled server at 96.126.130.126 on TCP port 58942.

CISA added CVE-2026-48558 to its Known Exploited Vulnerabilities (KEV) catalog on 2026-06-29 based on confirmed in-the-wild exploitation, triggering a Binding Operational Directive (BOD) 26-04 remediation deadline of 2026-07-02 for U.S. federal civilian agencies. Because SimpleHelp is widely deployed by managed service providers (MSPs) and IT service organizations to centrally administer client endpoints, a single compromised SimpleHelp instance can cascade into a multi-tenant supply-chain compromise, giving an attacker trusted administrative reach into every downstream organization managed through that instance.

MITRE ATT&CK techniques used in TL-2026-1122

Collection

T1005 Data from Local System; T1074 Data Staged; T1119 Automated Collection; T1560 Archive Collected Data

Discovery

T1016 System Network Configuration Discovery; T1057 Process Discovery; T1082 System Information Discovery; T1083 File and Directory Discovery; T1518 Software Discovery

Exfiltration

T1020 Automated Exfiltration; T1041 Exfiltration Over C2 Channel; T1567 Exfiltration Over Web Service

Lateral Movement

T1021 Remote Services

Defense Evasion

T1027 Obfuscated Files or Information; T1036 Masquerading; T1070 Indicator Removal; T1078 Valid Accounts; T1140 Deobfuscate/Decode Files or Information; T1497 Virtualization/Sandbox Evasion

Credential Access

T1056 Input Capture; T1111 Multi-Factor Authentication Interception; T1528 Steal Application Access Token; T1539 Steal Web Session Cookie; T1552 Unsecured Credentials; T1555 Credentials from Password Stores; T1606 Forge Web Credentials

Execution

T1059 Command and Scripting Interpreter; T1072 Software Deployment Tools; T1569 System Services

Command and Control

T1071 Application Layer Protocol; T1090 Proxy; T1102 Web Service; T1105 Ingress Tool Transfer; T1219 Remote Access Tools; T1568 Dynamic Resolution; T1572 Protocol Tunneling; T1573 Encrypted Channel

Persistence

T1098 Account Manipulation; T1136 Create Account

Initial Access

T1133 External Remote Services; T1190 Exploit Public-Facing Application; T1199 Trusted Relationship

Impact

T1531 Account Access Removal

lateral-movement

T1550 Use Alternate Authentication Material

defense-impairment

T1556 Modify Authentication Process

Resource Development

T1583 Acquire Infrastructure; T1587 Develop Capabilities

Reconnaissance

T1595 Active Scanning

Affected products and versions in SimpleHelp Authentication Bypass via Forged OIDC Tokens

  • SimpleHelp — SimpleHelp Remote Support / RMM Software
    Vulnerable versions: 5.5.15 and earlier 5.5.x releases; 6.0 pre-release builds prior to RC2
    Fixed in: 5.5.16; 6.0 RC2

Remediation for SimpleHelp Authentication Bypass via Forged OIDC Tokens

Patches

  • Upgrade to SimpleHelp 5.5.16 (5.5.x branch)
  • Upgrade to SimpleHelp 6.0 RC2 or later (6.0 branch)

Immediate actions

  • Apply SimpleHelp 5.5.16 (5.5.x branch) or 6.0 RC2 (6.0 branch) immediately; CISA BOD 26-04 set a 2026-07-02 remediation deadline for federal agencies
  • In the SimpleHelp admin console, navigate to Administration -> Technicians -> Gear Icon -> 'Show Group Authenticated Users' and review for any unfamiliar OIDC technician names or email addresses
  • Audit server logs at /opt/SimpleHelp/logs/server.log (or the dated /opt/SimpleHelp/logs/<YYYYMMDD-HHMMSS>/server.log subdirectories) for unrecognized technician logins or logins from unexpected source IPs
  • If immediate patching is not possible, disable OIDC/'Allow group authenticated logins' or disconnect the internet-facing SimpleHelp server from the network
  • Hunt for node.exe processes executing a file named jquery.js, and block outbound connections to a.dev-tunnels.com and 96.126.130.126:58942

Workarounds

  • Disable OIDC/SSO authentication providers on the SimpleHelp server until patched
  • Disconnect internet-facing SimpleHelp servers from the network if patching cannot occur immediately
  • Force re-authentication and rotate all Technician account credentials after patching or remediation

Longer-term hardening

  • Restrict SimpleHelp Technician login to an IP allow-list
  • Deploy EDR/behavioral detection on RMM and remote-support hosts to flag anomalous Node.js child-process execution and unsigned script execution
  • Segment RMM management infrastructure from general corporate and client networks to limit supply-chain blast radius
  • Require out-of-band, administrator-provisioned MFA that cannot be self-registered by a newly created account on first login
  • Establish continuous external attack-surface monitoring for internet-facing RMM/remote-support servers

CVEs associated with SimpleHelp Authentication Bypass via Forged OIDC Tokens

CVE-2026-48558

Weaknesses (CWE) in SimpleHelp Authentication Bypass via Forged OIDC Tokens

CWE-347, CWE-287, CWE-290, CWE-306

Timeline of SimpleHelp Authentication Bypass via Forged OIDC Tokens

  • Horizon3.ai identifies CVE-2026-48558 and validates its exploitability against SimpleHelp OIDC/Azure AD OIDC login flows in customer environments.
  • Horizon3.ai's Zach Hanley, via the firm's Sua Sponte autonomous research initiative, privately reports the OIDC signature-verification flaw to SimpleHelp.
  • SimpleHelp quietly ships fixed builds 5.5.16 and 6.0 RC2 without an associated public CVE identifier at time of release.
  • Horizon3.ai discovers SimpleHelp had already shipped a fix (5.5.16 / 6.0 RC2, Security Update 2026-05) without notifying the researchers, ahead of the researchers' planned coordinated-disclosure date.
  • Horizon3.ai publicly discloses CVE-2026-48558 with full technical detail and initial indicators of compromise; PoC exploit code is published on GitHub.
  • Follow-on reporting quantifies exposure: roughly 14,000 SimpleHelp servers are internet-facing, with approximately 7.2% (~1,000 servers) configured in the vulnerable OIDC/group-authentication mode.
  • CISA adds CVE-2026-48558 to the Known Exploited Vulnerabilities (KEV) catalog, triggering BOD 26-04 remediation requirements for federal civilian agencies.
  • BlackPoint Cyber's Adversary Pursuit Group publishes 'A Djinn in the Machine,' documenting a real intrusion where an attacker used CVE-2026-48558 to obtain a forged Technician session and deploy the TaskWeaver loader on an internet-facing SimpleHelp server.
  • Arctic Wolf and SOCRadar publish independent guidance and analysis on CVE-2026-48558 exploitation, credential-theft impact, and MSP remediation recommendations.
  • Multiple outlets (Help Net Security, BleepingComputer, The Hacker News, Arctic Wolf) report that the TaskWeaver Node.js loader delivers a previously undocumented cross-platform infostealer named Djinn Stealer.
  • Cyber Security News publishes summary coverage confirming active in-the-wild exploitation and CISA KEV listing.
  • BOD 26-04 remediation deadline passes for U.S. federal civilian agencies to apply mitigations for CVE-2026-48558.

Update history for TL-2026-1122

Sources cited for SimpleHelp Authentication Bypass via Forged OIDC Tokens

Threats related to SimpleHelp Authentication Bypass via Forged OIDC Tokens

Detection coverage for TL-2026-1122

As of 2026-07-11, Threadlinqs Intelligence publishes 9 detection rule(s) for TL-2026-1122 across Splunk SPL, Microsoft KQL and Sigma, covering 46 indicator(s) of compromise. The whole corpus is readable without an account; a free account unlocks full detection query text in Splunk SPL, Microsoft KQL and Sigma; paid tiers add raw indicator values, correlation and the MCP server. Threadlinqs MCP server · View plans.

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