CVE-2026-84803

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.

CVSS v3 9.0 CRITICAL

9.0^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 2.3 / Impact : 6.0

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-7h8j-qw37-w46g
https://www.vulncheck.com/advisories/siyuan-before-3.8.2-stored-xss-via-incomplete-asset-blocklist
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-7h8j-qw37-w46g

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-02 12:17

Updated : 2026-09-02 14:17

NVD link : CVE-2026-84803

Mitre link : CVE-2026-84803

CVE.ORG link : CVE-2026-84803

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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