SiYuan before v3.8.4 Missing Authorization via siyuan-send-windows
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-862.
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 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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| siyuan-note | siyuan | before 3.8.4 | 3.8.4 | Patch available | CNA |
- siyuan Vendorsiyuan-note Affected before 3.8.4 Fixed in 3.8.4 Patch available CNA
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:* | — | — | siyuan-note |
- cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:* Versions — — ·siyuan-note
Remediation
- Fix · CNA siyuan (siyuan-note) Fixed in 3.8.4
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
siyuan-note siyuan 3.8.4
14 records Highest priority Priority HIGH 11 HIGH, 2 MEDIUM, 1 LOW
Other records, highest priority first
- TI-2026-64804 SiYuan before v3.8.4 SQL Injection via dailyNoteSavePathPriority HIGH 77
- TI-2026-64806 SiYuan before v3.8.4 Authentication Bypass via Missing Origin HeaderPriority HIGH 72
- TI-2026-64805 SiYuan 3.7.0 before 3.8.4 Stored XSS via Gallery KanbanPriority HIGH 72
Timeline
- 2026-10-02 Threatist record created from CVE-2026-100634
- 2026-10-03 Alias added: GHSA-w745-gjg3-r76m
References
Patch 1
More siyuan-note vulnerabilities
- TI-2026-48492 SiYuan before v3.7.3 SQL Injection via searchDocs CVSS 4.0CRITICAL 9.9
- TI-2026-48491 SiYuan before v3.7.3 SQL Injection via searchEmbedBlock CVSS 4.0CRITICAL 9.9
- TI-2026-48490 SiYuan before v3.7.3 SQL Injection via fullTextSearchAssetContent CVSS 4.0CRITICAL 9.9
- TI-2026-47010 SiYuan before v3.7.2 Unauthenticated Administrator Takeover via MCP CVSS 4.0CRITICAL 10.0
- TI-2026-26050 SiYuan has directory traversal within its publishing service CVSS 3.1CRITICAL 9.8
- TI-2026-25256 SiYuan: Authorization Bypass Allows Arbitrary SQL Execution via Search API CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-100634 · CVE Program
- CVE-2026-100634 · NVD
- FIRST EPSS
- GHSA-w745-gjg3-r76m · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences