CVE-2026-25539
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.03%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.2 HIGHCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.03% probability · 62th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-22
- Affected
- b3log/siyuan
- Source
- security-advisories@github.com
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.