CVE-2026-100642: siyuan · Origin Validation Error
Affects siyuanSource CVE Database V5
Not known to be exploited · CVSS 7.2 High : upgrade to 3.8.4 soon.
Data as of 10 Nov 2026, 23:24 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% 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:L/VI:L/VA:H/SC:N/SI:N/SA:NExploitation 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 11 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. Until patched, users should avoid visiting untrusted web pages while authenticated to SiYuan to reduce risk of CSRF exploitation.
Description
SiYuan versions from v2.1.0 before v3.8.4 contain a cross-site request forgery vulnerability in the CheckAuth lock-screen pass-through branch that grants administrator access to loopback requests without validating Origin headers. Attackers can craft malicious web pages that force victims to terminate the kernel process, read workspace configuration and proxy settings, and trigger administrative actions via zero-credential cross-origin requests from the victim's browser.