{"schema":"threatline.record/2","record":{"id":"CVE-2026-100641","aliases":["GHSA-2mmf-4xwm-55rm"],"summary":"SiYuan before v3.8.4 Stored XSS via Unescaped Flashcard Content","details":"SiYuan before v3.8.4 does not HTML-escape stored flashcard block content before interpolating it into the card-manager list markup. Block content returned by /api/riff/getRiffCards is inserted into a card item template in app/src/card/viewCards.ts and assigned to listElement.innerHTML, so content such as <img src=invalid onerror=...> becomes an executable event-handler attribute. Because the SiYuan desktop (Electron) main window is created with nodeIntegration enabled and contextIsolation disabled, an administrator who opens the card manager on a workspace containing attacker-supplied flashcard content (for example introduced through contribution or import) executes the attacker's script in a privileged renderer, which can lead to arbitrary code execution on the host. The affected endpoint remains behind authentication and administrator-role checks; this is an untrusted-content-to-privileged-renderer issue, not an authorization bypass.","categories":["Unclassified"],"product":"siyuan","vendor":"siyuan-note","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-100641","source_modified_at":"2026-10-05T15:58:59.286Z","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-2026-100641","source_modified_at":"2026-10-05T15:58:59.286Z","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":0.00531,"percentile":0.44123,"score_date":"2026-10-23"},"published_at":"2026-09-26T13:23:13.957Z","modified_at":"2026-10-05T15:58:59.286Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-100641","fetched_at":"2026-10-23T18:52:38.922436Z","source_modified_at":"2026-10-05T15:58:59.286Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-100641","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-2mmf-4xwm-55rm","tags":["exploit"]},{"source":"CVE List","url":"https://github.com/siyuan-note/siyuan/commit/1ecb1c07de497ff03b585536fe5579291754d96b","tags":["patch"]},{"source":"CVE List","url":"https://github.com/siyuan-note/siyuan/commit/48c354e7de130aaada9d7120125bbc768344fd3b","tags":["patch"]},{"source":"CVE List","url":"https://github.com/siyuan-note/siyuan/commit/41b14025b4ac4a8379d1200580344ca18ad152b7","tags":["patch"]},{"source":"CVE List","url":"https://github.com/siyuan-note/siyuan/commit/8641553a1f07374001902d3ce773285db1292b2d","tags":["patch"]},{"source":"CVE List","url":"https://www.vulncheck.com/advisories/siyuan-before-3.8.4-stored-xss-via-unescaped-flashcard-content","tags":["third-party-advisory"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"poc","automatable":"no","technical_impact":"total","assessed_at":"2026-10-05T15:58:53.239401Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-05T15:58:59.286Z","content_hash":"6ed6584c50b587efb6a5d14853442a8534cfeb040f2fe86e4fc16b42740aadb2"}}