Description
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.
References (2)
Core 2
Core References
Exploit, Vendor Advisory x_refsource_confirm
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-c4jr-5q7w-f6r9
Scores
CVSS v3
9.1
EPSS
0.0024
EPSS Percentile
47.4%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
total
Details
CWE
CWE-22
Status
published
Products (2)
b3log/siyuan
< 3.5.3
siyuan-note/siyuan
0Go
Published
Feb 04, 2026
Tracked Since
Feb 18, 2026