CVE-2026-100634: siyuan · Missing Authorization
Affects siyuanSource CVE Database V5
Not known to be exploited · CVSS 5.3 Medium : upgrade to 3.8.4 when convenient.
Data as of 8 Nov 2026, 23:24 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.8.4
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:LExploitation evidence
Disclosed: evidence found.
CVE published 26 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.
What to do
Upgrade siyuan and siyuan-note/siyuan to 3.8.4.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| siyuan-notesiyuan | Affected
| Fixed in
|
GitHubsiyuan-note/siyuanpkg:github/siyuan-note/siyuanOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in SiYuan version 3.8.4 and later. Users should upgrade to version 3.8.4 or newer to remediate this vulnerability. No other mitigation steps are indicated.
Description
SiYuan note-taking software versions before 3.8.4 contain a missing authorization vulnerability in the 'siyuan-send-windows' IPC handler within the Electron main process. This flaw allows a renderer connected to a remote kernel to send commands that cause windows from other workspaces to lock repeatedly, resulting in a limited denial of service. There is no observed impact on confidentiality, integrity, or code execution.