CVE-2026-84803
SiYuan before v3.8.2 Stored XSS via incomplete asset blocklist
CVSS Score
9.0
EPSS Score
0.0%
EPSS Percentile
0th
SiYuan before v3.8.2 contains a stored cross-site scripting vulnerability in asset serving due to an incomplete extension blocklist that misses script-capable file types. Attackers can upload files with extensions like .xht, .ehtml, .xsl, .xbl, or .rdf that resolve to executable media types and execute JavaScript to steal API tokens and compromise workspaces.
| CWE | CWE-79 |
| Vendor | siyuan-note |
| Product | siyuan |
| Published | Sep 2, 2026 |
| Last Updated | Sep 2, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
siyuan-note / siyuan
0 < 3.8.2
References
Credits
🔍 Akokonunes