Vulnerability · Published Jan 29, 2026 · Assigned by VulnCheck

CVE-2026-25067SmarterTools SmarterMail < Build 9518 Unauthenticated background-of-the-day Path Coercion

Medium 6.9

In plain English

A medium-severity security flaw in SmarterMail from SmarterTools. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).

Severity (CVSS 4.0)6.9Medium

Exploit odds (30 days)0.3%top 76.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

SmarterTools SmarterMail versions prior to build 9518 contain an unauthenticated path coercion vulnerability in the background-of-the-day preview endpoint. The application base64-decodes attacker-supplied input and uses it as a filesystem path without validation. On Windows systems, this allows UNC paths to be resolved, causing the SmarterMail service to initiate outbound SMB authentication attempts to attacker-controlled hosts. This can be abused for credential coercion, NTLM relay attacks, and unauthorized network authentication.

Affected products (as reported)

Vendor	Product	Versions
SmarterTools	SmarterMail	0 – before 100.0.9518

Weakness: CWE-706 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

References

https://www.smartertools.com/smartermail/release-notes/current release-notes, patch
https://www.vulncheck.com/advisories/smartertools-smartermail-unauthenticated-background-of-the-day-path-coercion third-party-advisory