CVE-2025-21609 — CRITICAL (9.1)

Vulnerability Description

SiYuan is self-hosted, open source personal knowledge management software. SiYuan Note version 3.1.18 has an arbitrary file deletion vulnerability. The vulnerability exists in the `POST /api/history/getDocHistoryContent` endpoint. An attacker can craft a payload to exploit this vulnerability, resulting in the deletion of arbitrary files on the server. Commit d9887aeec1b27073bec66299a9a4181dc42969f3 fixes this vulnerability and is expected to be available in version 3.1.19.

CVSS Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
B3Log	Siyuan	3.1.18

Related Weaknesses (CWE)

CWE-459 CWE-552

References

https://github.com/siyuan-note/siyuan/commit/d9887aeec1b27073bec66299a9a4181dc42Patch
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-8fx8-pffw-w498ExploitVendor Advisory

FAQ

What is CVE-2025-21609?

CVE-2025-21609 is a vulnerability with a CVSS score of 9.1 (CRITICAL). SiYuan is self-hosted, open source personal knowledge management software. SiYuan Note version 3.1.18 has an arbitrary file deletion vulnerability. The vulnerability exists in the `POST /api/history/g...

How severe is CVE-2025-21609?

CVE-2025-21609 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2025-21609?

Check the references section above for vendor advisories and patch information. Affected products include: B3Log Siyuan.