CVE-2026-104083
SmarterMail before build 9777 contains a stored mutation cross-site scripting vulnerability that…
- Risk score
- 41/100
- CVSS
- 6.1 v3.1
- Exploit chance (30 days)
- 0.3%
- Published
- 9 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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 …
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 6.1 medium
References
Original 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.
Last activity 9 Oct 2026. Patch Forecast updates every hour.