{"id":"CVE-2026-100641","title":"SiYuan before v3.8.4 does not HTML-escape stored flashcard block content before interpolating it into the card-manager list markup","summary":"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/vi…","severity":"high","cvss":8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","cwe":["CWE-79"],"vendor":"siyuan-note","product":"siyuan","affected":["siyuan < 3.8.4"],"published":"2026-09-26","updated":"2026-09-26","sourceUpdated":"2026-09-26T14:16:46.193","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-100641","references":[{"url":"https://github.com/siyuan-note/siyuan/commit/1ecb1c07de497ff03b585536fe5579291754d96b","label":"disclosure@vulncheck.com"},{"url":"https://github.com/siyuan-note/siyuan/commit/41b14025b4ac4a8379d1200580344ca18ad152b7","label":"disclosure@vulncheck.com"},{"url":"https://github.com/siyuan-note/siyuan/commit/48c354e7de130aaada9d7120125bbc768344fd3b","label":"disclosure@vulncheck.com"},{"url":"https://github.com/siyuan-note/siyuan/commit/8641553a1f07374001902d3ce773285db1292b2d","label":"disclosure@vulncheck.com"},{"url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-2mmf-4xwm-55rm","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/siyuan-before-3.8.4-stored-xss-via-unescaped-flashcard-content","label":"disclosure@vulncheck.com"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-26T13:33:20.922Z","slug":"CVE-2026-100641","body":"## Overview\n\nSiYuan 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":44,"depthScoreParts":{"impact":44,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}