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[ CVE-2026-104083 · Published 9 Oct 2026 ]

Vulnerability in Smartertools Smartermail

CVSS 6.1 EPSS <1%1 agency advisoryNo fix listed yet

[ Description ]Official description

SmarterMail before build 9777 contains a stored mutation cross-site scripting vulnerability that allows remote attackers to inject executable script by placing payloads inside a <style> element nested within MathML foreign content (<math><mtext><mglyph>), which the custom HTML sanitizer treats as inert CDATA text but browsers reparse as live markup. Attackers can deliver a crafted calendar (iCal) message containing an <img src=x onerror=...> payload that executes automatically in the recipient's webmail session at /interface/message-iframe when the message is opened, enabling script execution and data exfiltration unconstrained by the interface's permissive Content-Security-Policy.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

[ References ]References