CVE-2026-55570CWE-116CWE-79CWE-94

SiYuan: Stored XSS results to Electron RCE in SiYuan marketplace via unescaped `data-obj` attribute (Bypass for CVE-2026-45375's patch)

Critical · published June 24, 2026

CVSS v3.1
9.0
EPSS
1%
Percentile
48.9
In the wild
Unconfirmed
What it is

SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, it does not escape the untrusted fields (name, version, author, description) when they are serialized into the data-obj HTML attribute of each marketplace card. Because the attribute is single-quoted and the value is produced with JSON.stringify() (which does not escape ', <, or >), a package whose name contains a single quote breaks out of the attribute and injects arbitrary HTML. In the desktop client the main BrowserWindow runs with nodeIntegration: true, contextIsolation: false, so the injected markup escalates from DOM XSS to arbitrary OS command execution. This is the same root cause and same impact as the original advisory, reached through a sibling sink the patch did not cover. This vulnerability is fixed in 3.7.0.

The record
Technical detail
CVSS v3.1
9.0 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00618 · 48.9th percentile
Weaknesses
CWE-116 · Improper Encoding or Escaping of Output; CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'); CWE-94 · Improper Control of Generation of Code ('Code Injection')
Published
2026-06-24T21:24Z
EPSS history
Timeline
  • 24 JUN 21:24Z
    SiYuan: Stored XSS results to Electron RCE in SiYuan marketplace via unescaped `data-obj` attribute (Bypass for CVE-2026-45375's patch)
    cvelistv5