{"schema":"threatline.record/2","record":{"id":"CVE-2026-104083","aliases":[],"summary":"SmarterMail < Build 9777 Stored Mutation XSS via MathML Foreign Content","details":"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.","categories":["Unclassified"],"product":"Smartermail","vendor":"Smartertools","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-104083","source_modified_at":"2026-10-13T16:54:35.632Z","fetched_at":"2026-10-23T18:48:36.087640Z","product":"Smartermail","vendor":"Smartertools","versions":[{"status":"affected","version":"0","versionType":"custom","lessThan":"Build 9777"}],"defaultStatus":"unaffected"}],"fixed_versions":[],"cvss":5.3,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00287,"percentile":0.20136,"score_date":"2026-10-23"},"published_at":"2026-10-09T15:06:57.154Z","modified_at":"2026-10-13T16:54:35.632Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-104083","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2026-10-13T16:54:35.632Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-104083","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://www.smartertools.com/smartermail/release-notes/current#/9526:~:text=Build%209777%20(Oct%208%2C%202026)","tags":["release-notes","patch"]},{"source":"CVE List","url":"https://blog.evan.lat/posts/sm/","tags":["technical-description","exploit"]},{"source":"CVE List","url":"https://www.vulncheck.com/advisories/smartermail-build-9777-stored-mutation-xss-via-mathml-foreign-content","tags":["third-party-advisory"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"none","automatable":"no","technical_impact":"partial","assessed_at":"2026-10-13T16:54:21.119344Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-13T16:54:35.632Z","content_hash":"7614bce286fb6c48cc1319e1a591865f16c68d600115be01539af2db3e2e4289"}}