{"id":"CVE-2026-100634","title":"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)","summary":"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 …","severity":"medium","cvss":4.7,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:L","cwe":["CWE-862"],"vendor":"siyuan-note","product":"siyuan","affected":["siyuan < 3.8.4"],"published":"2026-09-26","updated":"2026-09-26","sourceUpdated":"2026-09-26T14:16:44.957","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-100634","references":[{"url":"https://github.com/siyuan-note/siyuan/commit/8641553a1f07374001902d3ce773285db1292b2d","label":"disclosure@vulncheck.com"},{"url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-wxp7-xpq8-8xpm","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/siyuan-before-3.8.4-missing-authorization-via-siyuan-send-windows","label":"disclosure@vulncheck.com"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-26T13:33:20.926Z","slug":"CVE-2026-100634","body":"## Overview\n\nSiYuan 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":26,"depthScoreParts":{"impact":25.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}