{"id":"CVE-2026-100641","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-100641","generatedAt":"2026-10-27T23:45:21.956Z","title":"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.","description":"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.","published":"2026-09-26T14:16:46.000Z","lastModified":"2026-10-05T16:17:04.000Z","status":"Deferred","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":8.6,"severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-79"],"affected":[],"epss":{"score":0.00672,"percentile":0.51791,"date":"2026-10-26","history":[{"date":"2026-09-27","score":0.00531,"percentile":0.42638}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.67%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-26T14:16:46.000Z","detail":{"score":"8.6","severity":"HIGH","publishedAt":"2026-09-26T14:16:46.080Z"},"summary":"New CVE, high severity (CVSS 8.6)."}],"references":[{"url":"https://github.com/siyuan-note/siyuan/commit/1ecb1c07de497ff03b585536fe5579291754d96b","source":"disclosure@vulncheck.com"},{"url":"https://github.com/siyuan-note/siyuan/commit/41b14025b4ac4a8379d1200580344ca18ad152b7","source":"disclosure@vulncheck.com"},{"url":"https://github.com/siyuan-note/siyuan/commit/48c354e7de130aaada9d7120125bbc768344fd3b","source":"disclosure@vulncheck.com"},{"url":"https://github.com/siyuan-note/siyuan/commit/8641553a1f07374001902d3ce773285db1292b2d","source":"disclosure@vulncheck.com"},{"url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-2mmf-4xwm-55rm","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/siyuan-before-3.8.4-stored-xss-via-unescaped-flashcard-content","source":"disclosure@vulncheck.com"},{"url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-2mmf-4xwm-55rm","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-100641","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}