CVE-2026-34448: SiYuan: Stored XSS in Attribute View gallery/kanban cover rendering allows arbitrary command execution in the desktop client

Severity: critical (CVSS 9.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-03-31 · updated 2026-07-24
Weakness: CWE-79

Description

SiYuan is a personal knowledge management system. Prior to version 3.6.2, an attacker who can place a malicious URL in an Attribute View mAsse field can trigger stored XSS when a victim opens the Gallery or Kanban view with “Cover From -> Asset Field” enabled. The vulnerable code accepts arbitrary http(s) URLs without extensions as images, stores the attacker-controlled string in coverURL, and injects it directly into an <img src="..."> attribute without escaping. In the Electron desktop client, the injected JavaScript executes with nodeIntegration enabled and contextIsolation disabled, so the XSS reaches arbitrary OS command execution under the victim’s account. This issue has been patched in version 3.6.2.

Affected products

siyuan-note siyuan: before 3.6.2 — fixed in 3.6.2

How to fix

Upgrade to a fixed version: siyuan-note siyuan 3.6.2. Check the vendor advisory for mitigations.

References

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