CVE-2026-87811: SiYuan before v3.8.2 Stored XSS via notebook template paths
SiYuan before v3.8.2 inserts persisted notebook template paths into HTML input value attributes without proper attribute encoding. Attackers can craft malicious template paths that break out of the attribute context and execute JavaScript when a victim opens notebook configuration, enabling same-origin API requests and application state manipulation.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
SiYuanto a version that resolves this vulnerability.Fixed in 3.8.2
Event History
Frequently Asked Questions
Which SiYuan installations are affected?
SiYuan versions before v3.8.2 are affected. Upgrade to v3.8.2 or later to address the issue.
What must an attacker do for exploitation to occur?
The attacker needs low-level privileges to create or modify a persisted notebook template path with malicious content. A victim must then open the notebook configuration where that path is rendered.
What could successful exploitation allow?
JavaScript executes in the victim's SiYuan same-origin context. This can enable same-origin API requests and manipulation of application state.