CVE-2026-100643

What it is

SiYuan versions before v3.8.4 fail to properly escape four stored Attribute View values in textarea elements, allowing authenticated attackers to inject JavaScript by modifying field descriptions, template sources, select option descriptions, or footer calculation templates. Attackers can execute stored JavaScript when other users open affected database menus, and in the Electron desktop app with nodeIntegration enabled, this leads to command execution with SiYuan process privileges.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account, but needs a user to act. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-26 14:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-28 19:16 UTC Last updatedMost recent change to the record

Details

Published

2026-09-26 14:16 UTC

Last modified

2026-09-28 19:16 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-79 · Cross-site scripting

Record status

Deferred

Attack profile CVSS 4.0 · 8.5

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

Low

User interaction

Active

Confidentiality

High

Integrity

High

Availability

High