High severity · published Oct 9, 2026
CVE-2026-104082
SmarterMail < Build 9777 SysAdmin Remote Code Execution via Volume Mount
7.2
CVSS
0.9%
EPSS
No
On KEV
Description
SmarterMail before build 9777 contains a remote code execution vulnerability that allows an attacker holding a SysAdmin-scoped access token to bypass the Volume Mount script-directory containment control by provisioning a new mail domain with an arbitrary FileStore root path inside the trusted Scripts directory via the domain-put endpoint. Attackers can disclose the Scripts path through the AddOrUpdateMount endpoint, clear the upload extension blacklist via the global-mail endpoint, then upload a malicious script through the ordinary mail file-storage upload API so that saving a CommandMount triggers RunScript before validation, resulting in a reverse shell executing as the SmarterMail service account with SYSTEM-level privileges.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.9% · higher than 59% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SM
Smartermail · Smartertools
before Build 9777 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-104082
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-104082
release-notes
https://www.smartertools.com/smartermail/release-notes/current#/9526:~:text=Build%209777%20(Oct%208%2C%202026)
technical-description
https://blog.evan.lat/posts/sm/
third-party-advisory
https://www.vulncheck.com/advisories/smartermail-build-9777-sysadmin-remote-code-execution-via-volume-mount
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