CVE-2026-100634

SiYuan before v3.8.4 does not validate the sender or restrict recipients in the 'siyuan-send-windows' IPC handler of the Electron main process (app/electron/main.js). The handler ignores event.sender and forwards any received payload to every BrowserWindow returned by BrowserWindow.getAllWindows(), including windows belonging to other opened workspaces. A renderer connected to an attacker-controlled remote kernel can therefore send {cmd: "lockscreenByMode"} and have it delivered across the workspace boundary; a sibling workspace window whose lockScreenMode is set to 1 invokes lockScreen(). Repeated messages allow the remote workspace to repeatedly lock unrelated local workspace windows, causing a limited denial of service. No confidentiality, integrity, or code-execution impact was observed.

• https://github.com/siyuan-note/siyuan/commit/8641553a1f07374001902d3ce773285db1292b2d
• https://github.com/siyuan-note/siyuan/security/advisories/GHSA-wxp7-xpq8-8xpm
• https://www.vulncheck.com/advisories/siyuan-before-3.8.4-missing-authorization-via-siyuan-send-windows
• https://github.com/siyuan-note/siyuan/security/advisories/GHSA-wxp7-xpq8-8xpm