What it is
CVE-2026-24423 is an unauthenticated vulnerability affecting SmarterTools SmarterMail. SmarterTools SmarterMail versions prior to build 9511 contain an unauthenticated remote code execution vulnerability in the...
Vulnerability report
Exploited in the wild
Confirmed confidence
In CISA KEV
CVE-2026-24423
SmarterMail Remote Code Execution
SmarterTools / SmarterMail · affected before 100.0.9511
- Severity
- CVSS 9.3 · Critical
- Confidence
- Confirmed
- Exploit status
- Exploited in the wild
- EPSS
- 87.7%
- First observed
- —
- Last observed
- —
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.
Who is affected?
SmarterTools / SmarterMail affected before 100.0.9511.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
SmarterMail Remote Code Execution
SmarterTools SmarterMail versions prior to build 9511 contain an unauthenticated remote code execution vulnerability in the ConnectToHub API method. The attacker could point the SmarterMail to the malicious HTTP server, which serves the malicious OS command.
This command will be executed by the vulnerable application.
Vendor
Product
Affected
Status
SmarterTools
SmarterMail
Before 100.0.9511
Affected
- Published
- 23 Jan 2026
- Exploitation Reported
- 01 Jun 2026
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- None
- User interaction
- None
Tags
cisa
nuclei_scanner
malware
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-24423
- Patch — smartertools.com smartertools.com · Patch https://www.smartertools.com/smartermail/release-notes/current
- Third-Party Advisory — code-white.com code-white.com · Third-Party Advisory https://code-white.com/public-vulnerability-list/#systemadminsettings...
- Third-Party Advisory — vulncheck.com vulncheck.com · Third-Party Advisory https://www.vulncheck.com/advisories/smartertools-smartermail-unauthe...
Exploitation evidence
Why KEV Intelligence 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
CVE
Independent exploitation attestation added to the KEV Intelligence record.
Used in malware
CVE
Malware families have been linked to exploitation of this CVE.
Proof of concept available
GitHub
Public scanner or PoC coverage increases practical exploitability.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CVE First | 2026-06-01 10:50 UTC |
| CISA | 2026-06-02 14:03 UTC |
| The Shadowserver | 2026-07-08 00:00 UTC |
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 0
- User-Agents
- 0
Raw values available in Pro and Enterprise.
Scanner coverage
Nuclei template detected 01 Jun 2026.
View Nuclei template (opens in new tab)Virtual patch status
No KEV Intelligence 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-2026-24423.yaml | 01 Jun 2026 |
Risk and context
Severity, weaknesses, and research context
CVSS v4.0
9.3
Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS
87.7%
All CVSS Scores
CVSS v4.0
9.3
Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS v3.1
9.8
Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
SmarterMail - Remote Code Execution
nuclei · Created Unknown
Timeline
From disclosure to observed exploitation
-
KEV confirmed by The Shadowserver
Exploitation attested by an external source
-
Public PoC available
Public proof-of-concept code published
-
First public exploitation report
Exploit observed in malware
-
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
Nuclei template available
Scanner coverage available
-
Added to KEV Intelligence KEV Feed
High-confidence, third-party attested exploitation
-
CVE published
Vulnerability disclosed publicly
-
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.
- 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-2026-24423
Free JSON includes basic KEV fields{
"cve_id": "CVE-2026-24423",
"confidence": "Confirmed",
"cvss_score": 9.3,
"cvss_estimated": false,
"epss_score": 0.87693,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}Early warning alerts
Get alerts on high-impact exploitation
Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.