CVE-2026-48558
Confirmed PUBLISHEDSimpleHelp Authentication Bypass via Missing OIDC JWT Signature Verification
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
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.
- CVE Published
- Jun 12, 2026
- Exploitation Reported
- Jun 29, 2026
- CVSS
- 9.5 Critical
- EPSS
- 0.7%
CVE References
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel 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 |
| TheHackerNews | 2026-06-30 12:20 UTC |
No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users via the Pro API.
Learn About Virtual PatchesCVSS Scores
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:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Exploitation Status
Exploited in the wild
Recorded 2026-06-29 14:20:22 UTC · BleepingComputer
Weaknesses (CWE)
-
Improper Verification of Cryptographic Signature
Recent Mentions
TheHackerNews · Jun 30, 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
Dark Reading · Jun 29, 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.
BleepingComputer · Jun 29, 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. [...]
All CISA Advisories · Jun 29, 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 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 Nomination Form. Potential KEV additions must have a CVE ID, evidence of exploitation, and clear mitigation guidance.
Horizon3.ai Attack Research · Jun 12, 2026
Horizon3.ai details indicators of compromise, affected configurations, and mitigation guidance for CVE-2026-48558, a SimpleHelp OIDC authentication bypass vulnerability.
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
12:20 UTC about 3 hours ago12:20 UTC · about 3 hours ago
KEV confirmed by TheHackerNews
Exploitation attested by an external source
-
21:20 UTC about 18 hours ago21:20 UTC · about 18 hours ago
KEV confirmed by All CISA Advisories
Exploitation attested by an external source
-
20:20 UTC about 19 hours ago20:20 UTC · about 19 hours ago
KEV confirmed by CVE
Exploitation attested by an external source
-
14:20 UTC 1 day ago14:20 UTC · 1 day ago
KEV confirmed by BleepingComputer
Exploitation attested by an external source
-
00:00 UTC 1 day ago00:00 UTC · 1 day ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
17:07 UTC 18 days ago17:07 UTC · 18 days ago
CVE published
Vulnerability disclosed publicly
-
18:34 UTC about 1 month ago18:34 UTC · about 1 month ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2026-48558
{
"cve_id": "CVE-2026-48558",
"title": "SimpleHelp Authentication Bypass via Missing OIDC JWT Signature Verification",
"affected_vendor": "SimpleHelp",
"affected_product": "SimpleHelp",
"confidence": "Confirmed",
"cvss_score": 9.5,
"epss_score": 0.00721,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}