{"schema":"threatline.record/2","record":{"id":"CVE-2026-100639","aliases":["GHSA-2cmm-9x9j-rvff"],"summary":"SiYuan before v3.8.4 Cross-Site Scripting via Kramdown IAL","details":"SiYuan v3.8.3 fails to HTML-escape the data-subtype attribute when generating gutter-button markup (app/src/protyle/gutter/button.ts, assigned via innerHTML in app/src/protyle/gutter/index.ts) from content pasted as plain-text Markdown containing a Kramdown inline attribute list (IAL). Because the shared Lute renderer parses Kramdown IAL from text/plain input, an attacker-supplied Markdown snippet using entity-encoded quotes in data-subtype breaks out of the attribute value when the gutter markup is re-parsed by the browser, injecting additional attributes such as autofocus and onfocus. If a victim pastes the crafted Markdown and the affected gutter control receives focus, the injected handler executes; in the Electron desktop application, where the main BrowserWindow enables Node integration and disables context isolation, this results in JavaScript execution with renderer Node.js privileges (remote code execution). Fixed in v3.8.4.","categories":["Unclassified"],"product":"siyuan","vendor":"siyuan-note","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-100639","source_modified_at":"2026-09-28T18:51:14.199Z","fetched_at":"2026-10-23T18:52:38.922436Z","product":"siyuan","vendor":"siyuan-note","versions":[{"version":"0","status":"affected","versionType":"semver","lessThan":"3.8.4"},{"version":"3.8.4","status":"unaffected","versionType":"semver"}],"defaultStatus":"unaffected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-100639","source_modified_at":"2026-09-28T18:51:14.199Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"siyuan","ecosystem":null},"version":"3.8.4","basis":"first unaffected version stated in the CVE record"}],"cvss":8.6,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00472,"percentile":0.399,"score_date":"2026-10-23"},"published_at":"2026-09-26T13:23:12.602Z","modified_at":"2026-09-28T18:51:14.199Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-100639","fetched_at":"2026-10-23T18:52:38.922436Z","source_modified_at":"2026-09-28T18:51:14.199Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-100639","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-2cmm-9x9j-rvff","tags":["exploit"]},{"source":"CVE List","url":"https://www.vulncheck.com/advisories/siyuan-before-3.8.4-cross-site-scripting-via-kramdown-ial","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":"total","assessed_at":"2026-09-28T18:49:39.724850Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-09-28T18:51:14.199Z","content_hash":"9985a1988eed0eee2504843a1d4699818b996d550e2d6ea23f3d88f2e4db7c01"}}