CVE-2025-21609Public exploitNetwork attack vector

Arbitrary file deletion via unchecked history path

Published Jan 3, 2025 · Updated Jan 3, 2025

Arbitrary file deletion in SiYuan Note 3.1.18 allows remote attackers to delete server files through a crafted history request. The getDocHistoryContent flow accepts an absolute historyPath outside the workspace and calls os.RemoveAll when that file fails JSON parsing. No authentication or user interaction is required, and deletion is limited to files the SiYuan process can access.

CVSS severity8.7
High
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Arbitrary file deletion in SiYuan Note 3.1.18 allows remote attackers to delete server files through a crafted history request. The getDocHistoryContent flow accepts an absolute historyPath outside the workspace and calls os.RemoveAll when that file fails JSON parsing. No authentication or user interaction is required, and deletion is limited to files the SiYuan process can access.

The record

CVE
CVE-2025-21609
Published
Jan 3, 2025
Updated
Jan 3, 2025
Vendor
SiYuan Note
Product
SiYuan
Classifications
CWE-552, CWE-459, T1485
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 3, 2025CVE publishedPublication date reported by the CVE source.
  2. Jan 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion== 3.1.18

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SiYuan Note · SiYuanversion== 3.1.18

Published CVSS scores

8.7GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
9.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-552Files or Directories Accessible to External Parties
CWE-459Incomplete Cleanup
T1485Data Destruction

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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