CVE-2026-87812: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in siyuan-note siyuan
SiYuan before v3.8.2 contains a stored cross-site scripting vulnerability in Bazaar package cards where the iconURL metadata is inserted directly into HTML img src attributes without escaping. Attackers can inject malicious URLs with event handlers that execute JavaScript in the authenticated SiYuan origin when users view Bazaar listings, enabling API requests and application state manipulation.
AI Analysis
Technical Summary
CVE-2026-87812 is a stored cross-site scripting vulnerability affecting SiYuan versions prior to 3.8.2. The flaw exists in the Bazaar package cards feature, where the iconURL metadata is embedded directly into the src attribute of img tags without proper neutralization or escaping. This improper input handling enables attackers to inject malicious URLs containing event handlers that execute arbitrary JavaScript code within the authenticated user's browser session. Exploitation can lead to unauthorized API requests and manipulation of the application state within the SiYuan environment.
Potential Impact
Successful exploitation allows an attacker to execute arbitrary JavaScript in the context of authenticated SiYuan users when they view Bazaar listings. This can lead to unauthorized API requests and manipulation of the application state, potentially compromising user data or application integrity. The vulnerability does not require privileges but does require user interaction (viewing the affected content).
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Users should upgrade to SiYuan version 3.8.2 or later once available. Until then, avoid viewing untrusted Bazaar package listings or disable the Bazaar feature if possible to reduce exposure.
CVE-2026-87812: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in siyuan-note siyuan
Description
SiYuan before v3.8.2 contains a stored cross-site scripting vulnerability in Bazaar package cards where the iconURL metadata is inserted directly into HTML img src attributes without escaping. Attackers can inject malicious URLs with event handlers that execute JavaScript in the authenticated SiYuan origin when users view Bazaar listings, enabling API requests and application state manipulation.
CVSS v4.0
Score 7.4high
Affected software
pkg:github/siyuan-note/siyuanRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-87812 is a stored cross-site scripting vulnerability affecting SiYuan versions prior to 3.8.2. The flaw exists in the Bazaar package cards feature, where the iconURL metadata is embedded directly into the src attribute of img tags without proper neutralization or escaping. This improper input handling enables attackers to inject malicious URLs containing event handlers that execute arbitrary JavaScript code within the authenticated user's browser session. Exploitation can lead to unauthorized API requests and manipulation of the application state within the SiYuan environment.
Potential Impact
Successful exploitation allows an attacker to execute arbitrary JavaScript in the context of authenticated SiYuan users when they view Bazaar listings. This can lead to unauthorized API requests and manipulation of the application state, potentially compromising user data or application integrity. The vulnerability does not require privileges but does require user interaction (viewing the affected content).
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Users should upgrade to SiYuan version 3.8.2 or later once available. Until then, avoid viewing untrusted Bazaar package listings or disable the Bazaar feature if possible to reduce exposure.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-09-09T10:30:15.669Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6aa14507acd9273b49403558
Added to database: 09/09/2026, 11:37:43 UTC
Last enriched: 09/09/2026, 11:52:38 UTC
Last updated: 09/09/2026, 21:36:41 UTC
Views: 7
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