Critical severity · published Jun 12, 2026
CVE-2026-48558
SimpleHelp Authentication Bypass via Missing OIDC JWT Signature Verification
In wildKEV
10.0
CVSS
77.7%
EPSS
Yes
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)77.7% · higher than 100% of CVEs
Exploited in the wildYes
CISA KEVListed Jun 29, 2026
Federal remediation dueJul 2, 2026
Ransomware campaign useNot known
Affected products
Which versions
SI
SimpleHelp · SimpleHelp
5.5.0 before 5.5.16; 6.0 before 6.0 RC2 · source: vendor, NVD, KEV
In the news
VulnerabilityCritical
U.S. CISA adds SimpleHelp flaw to its Known Exploited Vulnerabilities catalog
U.S. Cybersecurity and Infrastructure Security Agency (CISA) adds a SimpleHelp flaw to its Known Exploited Vulnerabilities catalog. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) added a SimpleHelp flaw, tracked as CVE-2026-48558 (CVSS score v3.1 of 10.0), to its Known Exploited Vulnerabilities (KEV) catalog. CVE-2026-48558 is a critical authentication bypass vulnerability in SimpleHelp versions 5.5.15 and earlier and […]
Jun 30, 2026·Security Affairs
VulnerabilityCritical
Attackers Exploit SimpleHelp CVE-2026-48558 to Deploy TaskWeaver and Djinn Stealer
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
Jun 30, 2026·The Hacker News
VulnerabilityHigh
SimpleHelp vulnerability exploited to deliver mighty Djinn Stealer (CVE-2026-48558)
Attackers are exploiting CVE-2026-48558, a recently patched authentication bypass vulnerability in SimpleHelp RMM, to drop the novel Djinn Stealer malware on victim computers. The malware is capable of targeting Windows, macOS, and Linux systems, and “collects credentials associated with cloud platforms, source control, package registries, infrastructure tooling, AI development assistants, browsers, SSH, and cryptocurrency wallets,” BlackPoint Cyber’s researchers discovered. CVE-2026-48558 exploited SimpleHelp is a remote monitoring and management (RMM) tool popular with managed services providers … More →
The post SimpleHelp vulnerability exploited to deliver mighty Djinn Stealer (CVE-2026-48558) appeared first on Help Net Security .
Jun 30, 2026·Help Net Security
VulnerabilityCritical
'Djinn' Stealer Targets Cloud, AI Credentials
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.
Jun 29, 2026·Dark Reading
BreachCritical
Critical SimpleHelp flaw exploited to deploy new stealer malware
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. [...]
Jun 29, 2026·BleepingComputer
VulnerabilityHigh
CISA Adds One Known Exploited Vulnerability to Catalog
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 federal agencies to prioritize rapid remediation of high-risk vulnerabilities, specifically those identified by Common Vulnerabilities and Exposures (CVEs) listed in CISA’s KEV Catalog on publicly exposed assets that grant total control of the asset post-exploitation, while deferring action for lower-risk vulnerabilities. BOD 26-04 further establishes basic expectations for when agencies must check whether threat actors compromised the system before the patch was applied.
While BOD 26-04 applies only to FCEB agencies, CISA encourages all organizations to adopt risk-based vulnerability management and prioritize remediation of KEV Catalog vulnerabilities . CISA will continue to add vulnerabilities to the catalog that meet the specified criteria .
Aware of an exploited vulnerability not currently listed in the KEV Catalog? Submit it for potential addition through CISA’s KEV N...
Jun 29, 2026·CISA Advisories
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-48558
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-48558
CISA KEV catalogue
https://www.cisa.gov/known-exploited-vulnerabilities-catalog
technical-description
https://horizon3.ai/attack-research/disclosures/cve-2026-48558-simplehelp-authentication-bypass-iocs/
vendor-advisory
https://simple-help.com/security/simplehelp-security-update-2026-05
release-notes
https://simple-help.com/release-news
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