CVE-2026-55570

CRITICAL
INFO Priority: 0.04 BB Relevance: 58/100
Published: 2026-06-24 Modified: 2026-10-25 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity Conf. Impact Integ. Impact Scope Change

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: Required
S: Changed
C: High
I: High
A: High

Description

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.

Weakness Classification (3)

Bug Bounty Relevance

58 / 100
✓ Network accessible
✓ Low complexity

CVSS Score

9.0 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

EPSS — Exploitation Probability

0.40%
Raw Score 0.004020
Percentile 34.4%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00402
2026-10-28
0.00402

Intelligence Sources

nvd ref →