CVE-2026-87811

High

Description

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.

SeverityHigh

CVSS7.3

Exploit probability—

ProductSiyuan

PublishedSep 9, 2026

First seenSep 9, 2026

Weakness typeCWE-79Cross-site scripting (XSS)

How to fix

Update

siyuan-note siyuan3.8.2 or later

Vendor advisories

github.com/siyuan-note/siyuan/security/advisories/GHSA-v6wf-r2gr-rrgf

Affected products

Product	Affected versions	Fixed in
siyuan-note siyuan	v < 3.8.2	3.8.2

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.