SmarterTools SmarterMail Missing Authentication for Critical Function Vulnerability
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…
Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.
Exploitation probability EPSS · FIRST
Exploitation signals 5 / 5
- KEV catalog (CISA)05 Feb 2026
- Exploited in EUVD (ENISA)05 Feb 2026
- Used by ransomwareyes
- EPSS above 10 %88.2%
- No account, over the networkyes
What to do
Fix
Apply the vendor’s fix as soon as it is available.
CISA guidance: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Meanwhile
Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.
Manufacturers (CRA)
Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained
Description ENISA EUVD
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.
Affected products
- 0 <100.0.9511
Open source packages OSV
Affected libraries according to OSV, with fixed versions.
Timeline
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Published
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Exploitation reported (ENISA)
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Added to the KEV catalog
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CISA remediation due date
-
EPSS peak: 88.2%
References
Other exploited vulnerabilities from the same vendor
- CVE-2026-23760SmarterTools SmarterMail Authentication Bypass Using an Alternate Path or Channel Vulnerability9.6 · Background exploitation
- CVE-2025-52691SmarterTools SmarterMail Unrestricted Upload of File with Dangerous Type Vulnerability9.6 · Background exploitation