CVE-2026-54158: siyuan-note siyuan Cross-site Scripting

Vulnerability summary

CVE-2026-54158 is a critical (CVSS 9.9) Cross-site Scripting vulnerability in siyuan-note siyuan. EPSS estimates a 0.51% chance of exploitation in the next 30 days, higher than 42.1% of scored vulnerabilities.

Timeline

1. 24-06-2026
   PublishedVulnerability first disclosed.
2. 25-06-2026
   Last modifiedVulnerability information updated.

Description

SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, the attribute-view (database) cell renderer genAVValueHTML interpolates cell content raw in four of its branches: text, url, phone, and mAsset. A cell value like </textarea><img src=x onerror="..."> or "><img src=x onerror="..."> breaks out of its surrounding tag and runs arbitrary JavaScript in the renderer when the victim opens the block-attribute panel. On Electron desktop the renderer runs with nodeIntegration:true, so the XSS chains to host RCE via require('child_process'). AV files live under the workspace and ride normal sync, so an attacker with write access to any synced workspace plants the payload once and it fires on every device that opens a panel containing that row.he kernel doesn't escape on the way in either, so the malicious cell persists byte-for-byte. There's no equivalent of the html.EscapeAttrVal call that protects block IAL attributes at kernel/model/blockial.go:261. This vulnerability is fixed in 3.7.0.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
• CWE-1188Initialization of a Resource with an Insecure DefaultThe product initializes or sets a resource with a default that is intended to be changed by the product's installer, administrator, or maintainer, but the default is not secure.