{"id":"CVE-2026-104083","aliases":["EUVD-2026-95888","GHSA-vvh8-jc22-6q2f"],"status":"published","title":"SmarterMail \u003c Build 9777 Stored Mutation XSS via MathML Foreign Content","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 \u003cstyle\u003e element nested within MathML foreign content (\u003cmath\u003e\u003cmtext\u003e\u003cmglyph\u003e), 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 \u003cimg src=x onerror=...\u003e 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.","severity":{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00326,"percentile":0.26033,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2026-10-09T15:06:57Z","modified":"2026-10-27T01:30:36Z","products":[{"vendor":"smartertools","product":"smartermail"},{"vendor":"smartertools inc.","product":"smartermail"}],"references":[{"url":"https://www.smartertools.com/smartermail/release-notes/current#/9526:~:text=Build%209777%20(Oct%208%2C%202026)","tags":["release-notes","patch"]},{"url":"https://blog.evan.lat/posts/sm/","tags":["technical-description","exploit"]},{"url":"https://www.vulncheck.com/advisories/smartermail-build-9777-stored-mutation-xss-via-mathml-foreign-content","tags":["third-party-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-104083"},{"url":"https://blog.evan.lat/posts/sm"},{"url":"https://github.com/advisories/GHSA-vvh8-jc22-6q2f"}],"sources":{"cve":[{"id":"CVE-2026-104083","title":"SmarterMail \u003c Build 9777 Stored Mutation XSS via MathML Foreign Content","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 \u003cstyle\u003e element nested within MathML foreign content (\u003cmath\u003e\u003cmtext\u003e\u003cmglyph\u003e), 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 \u003cimg src=x onerror=...\u003e 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.","status":"published","published":"2026-10-09T15:06:57.154Z","modified":"2026-10-27T01:30:36.776Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:20:09.448255Z"}],"euvd":[{"id":"EUVD-2026-95888","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 \u003cstyle\u003e element nested within MathML foreign content (\u003cmath\u003e\u003cmtext\u003e\u003cmglyph\u003e), 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 \u003cimg src=x onerror=...\u003e 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.","status":"published","published":"2026-10-09T15:06:57Z","modified":"2026-10-27T01:30:36Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","level":"medium"}],"updated_at":"2026-11-02T16:59:25.230426Z"}],"ghsa":[{"id":"GHSA-vvh8-jc22-6q2f","title":"SmarterMail before build 9777 contains a stored mutation cross-site scripting vulnerability that...","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 \u003cstyle\u003e element nested within MathML foreign content (\u003cmath\u003e\u003cmtext\u003e\u003cmglyph\u003e), 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 \u003cimg src=x onerror=...\u003e 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.","status":"published","published":"2026-10-09T18:31:42Z","modified":"2026-10-12T15:33:13Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium"},{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:13:06.481163Z"}],"nvd":[{"id":"CVE-2026-104083","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 \u003cstyle\u003e element nested within MathML foreign content (\u003cmath\u003e\u003cmtext\u003e\u003cmglyph\u003e), 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 \u003cimg src=x onerror=...\u003e 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.","status":"published","published":"2026-10-09T16:17:20.993Z","modified":"2026-10-13T17:17:15.5Z","cvss":[{"version":"4.0","score":5.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:55.473789Z"}]}}