CVE-2026-23851 HIGH

CVE-2026-23851: SiYuan Vulnerable to Arbitrary File Read via File Copy Functionality

Vendor Siyuan-Note
Product siyuan
Weakness CWE-22 · Path traversal
Published January 19, 2026
Last update January 20, 2026

CVSS base score

8.3/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N

What the vulnerability does

01Description

SiYuan is a personal knowledge management system. Versions prior to 3.5.4 contain a logic vulnerability in the /api/file/globalCopyFiles endpoint. The function allows authenticated users to copy files from any location on the server's filesystem into the application's workspace without proper path validation. The vulnerability exists in the api/file.go source code. The function globalCopyFiles accepts a list of source paths (srcs) from the JSON request body. While the code checks if the source file exists using filelock.IsExist(src), it fails to validate whether the source path resides within the authorized workspace directory. Version 3.5.4 patches the issue.

Key dates

02Disclosure timeline

January 19, 2026 CVE published
January 20, 2026 Record updated