CVE-2026-25539 — SiYuan has Arbitrary File Write via /api/file/copyFile leading to RCE
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 w…
Published: 2026-02-04 · CVSS: 9.1 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7