How broadly exploitable is this vulnerability?

Exploitation is limited to authenticated users who can call the /api/file/copyFile endpoint, but within that scope it can be highly impactful. In environments where the application account can write to sensitive system or user directories, an attacker may leverage this to achieve remote code execution or persistent access.

Does exploitation require privileged credentials or local access?

No local system access is required, but valid authentication to the SiYuan instance is needed. The attacker must be able to send crafted HTTP requests to the vulnerable endpoint; privilege requirements beyond basic authentication depend on how the application authorizes file operations.

What is the safest general fix pattern for developers?

Constrain all filesystem operations to an application-controlled root directory, canonicalize incoming paths, and reject any request that attempts to escape that boundary. Additionally, avoid exposing raw filesystem paths in APIs and instead operate on internal identifiers that the server maps to safe locations.

Severity:

CRITICAL RISK

(9.1)

Path Traversal (CWE-22) in SiYuan /api/file/copyFile Allows Arbitrary File Write

CVE-2026-25539

Published:

Feb 4, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

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CRITICAL RISK

CRITICAL

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Account Takeover / Loss of Account Control

February 17, 2026

CWE-77;CWE-78

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in node-sonos-http-api TTS Provider for macOS

Remote Code Execution on the Server Host

February 17, 2026

Vulnerability Type

Category:

Path Traversal / Arbitrary File Write

CWE:

CWE-22

Impact:

Remote Code Execution via Arbitrary File Write

Severity:

CRITICAL RISK

(9.1)

CVSS Version:

3.1

Vulnerability Type

Category:

Path Traversal / Arbitrary File Write

CWE:

CWE-22

Impact:

Remote Code Execution via Arbitrary File Write

Severity:

CRITICAL RISK

(9.1)

CVSS Version:

3.1

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Path Traversal (CWE-22) in SiYuan /api/file/copyFile Allows Arbitrary File Write

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

CRITICAL RISK

CRITICAL

(9.8)

Missing Authentication for Forgot-Password Email Change API (CWE-306)

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in node-sonos-http-api TTS Provider for macOS

Vulnerability Type

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

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