# CVE-2025-21609

## Summary

- **CVE ID:** CVE-2025-21609
- **Severity:** HIGH
- **CVSS Score:** 8.7 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N)
- **CWE:** CWE-459, CWE-552
- **Published:** Jan 3, 2025
- **Last Modified:** Mar 12, 2026

## 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.

## Affected Products

- siyuan-note — siyuan (= 3.1.18)

## References

- [CNA](https://github.com/siyuan-note/siyuan/security/advisories/GHSA-8fx8-pffw-w498)
- [CNA](https://github.com/siyuan-note/siyuan/commit/d9887aeec1b27073bec66299a9a4181dc42969f3)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.60%
- **EPSS Percentile:** 46.6

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._