critical · CVSS v3 8 · CVSS v4 8.6
CVE-2026-100641
SiYuan before v3.8.4 does not HTML-escape stored flashcard block content before interpolating it into the card-manager l…
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 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.
Scores
- Severity
- critical
- CVSS v2
- 9
- CVSS v3
- 8
- CVSS v4
- 8.6
- EPSS
- —