Track vulnerabilities like this one. Sign up free to get alerted when software you use is affected.
8.9

SiYuan lets attackers perform admin actions via forged request

CVE-2026-100642 · published 1 month ago
Summary

Versions of SiYuan from 2.1.0 up to, but not including, 3.8.4 can be tricked into accepting forged web requests that give an attacker administrative control without needing a password. This could let a user’s browser unintentionally change settings, read configuration data, or stop the application. Upgrade to version 3.8.4 or later, or apply the vendor’s recommended configuration changes, to stop the problem.

What to do
  • Update siyuan-note siyuan to version 3.8.4 or later.
Affected software
VendorProductAffected versions
siyuan-note siyuan < 3.8.4
Original advisory text
SiYuan v2.1.0 before v3.8.4 Cross-Site Request Forgery via CheckAuth
SiYuan versions from v2.1.0 before v3.8.4 contain a cross-site request forgery vulnerability in the CheckAuth lock-screen pass-through branch that grants administrator access to loopback requests without validating Origin headers. Attackers can craft malicious web pages that force victims to terminate the kernel process, read workspace configuration and proxy settings, and trigger administrative actions via zero-credential cross-origin requests from the victim's browser.
References
Fix within
Internet-facing 60 days
Internal At next upgrade
  • Not known to be exploited
  • Needs hands-on effort to exploit
  • Gives an attacker partial control
Severity
8.9 High
Exploitation
<1% chance of attack within 30 days
Type
CWE-346Origin Validation Error
Timeline
Published26 Sep 2026
Updated26 Oct 2026
First seen26 Sep 2026
Sources
CVE-2026-100642 · NVD
CVE-2026-100642 · MITRE
CVE-2026-100642 · OSV
GHSA-9gpj-3rm3-x42m · GHSA
Track software like this
Free during beta