CVE-2026-100641: siyuan · Cross-site Scripting
Affects siyuanSource CVE Database V5
Not known to be exploited · CVSS 8.6 High : upgrade to 3.8.4 soon.
Data as of 8 Nov 2026, 23:24 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 52% 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:L/UI:P/VC:H/VI:H/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 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. Until upgrading, administrators should avoid opening the card manager on workspaces containing untrusted or attacker-controlled flashcard content.
Description
SiYuan note-taking software versions before 3.8.4 contain a cross-site scripting (XSS) vulnerability due to improper HTML escaping of flashcard block content. This flaw allows attacker-supplied content to execute scripts in a privileged renderer context when an administrator views the card manager. The vulnerability requires authentication and administrator privileges to exploit and can lead to arbitrary code execution on the host system.
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-2mmf-4xwm-55rm (opens in a new tab)
- github.com/siyuan-note/siyuan/commit/1ecb1c07de497ff03b585536fe5579291754d96b (opens in a new tab)
- github.com/siyuan-note/siyuan/commit/48c354e7de130aaada9d7120125bbc768344fd3b (opens in a new tab)
- github.com/siyuan-note/siyuan/commit/41b14025b4ac4a8379d1200580344ca18ad152b7 (opens in a new tab)
- github.com/siyuan-note/siyuan/commit/8641553a1f07374001902d3ce773285db1292b2d (opens in a new tab)
- vulncheck.com/advisories/siyuan-before-3.8.4-stored-xss-via-unescaped-flashcard-content (opens in a new tab)