CVE-2026-25539criticalCWE-22

CVE-2026-25539: critical vulnerability in siyuan-note siyuan

SiYuan has Arbitrary File Write via /api/file/copyFile leading to RCE

Published · Updated

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

28Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 9.1epss 1.1%
SiYuan is a personal knowledge management system. Prior to version 3.5.5, the /api/file/copyFile endpoint does not validate the dest parameter, allowing authenticated users to write files to arbitrary locations on the filesystem. This can lead to Remote Code Execution (RCE) by writing to sensitive locations such as cron jobs, SSH authorized_keys, or shell configuration files. This issue has been patched in version 3.5.5.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Affected products
siyuan-note · siyuan