CVE-2026-33476
Received Received - Intake
Directory Traversal in SiYuan Kernel Allows Unauthenticated File Access

Publication date: 2026-03-20

Last updated on: 2026-03-23

Assigner: GitHub, Inc.

Description
SiYuan is a personal knowledge management system. Prior to version 3.6.2, the Siyuan kernel exposes an unauthenticated file-serving endpoint under `/appearance/*filepath.` Due to improper path sanitization, attackers can perform directory traversal and read arbitrary files accessible to the server process. Authentication checks explicitly exclude this endpoint, allowing exploitation without valid credentials. Version 3.6.2 fixes this issue.
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Meta Information
Published
2026-03-20
Last Modified
2026-03-23
Generated
2026-06-16
AI Q&A
2026-03-21
EPSS Evaluated
2026-06-15
NVD
CVE-2026-33476
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
b3log siyuan to 3.6.2 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-73 The product allows user input to control or influence paths or file names that are used in filesystem operations.
CWE-22 The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
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Executive Summary

The vulnerability exists in the SiYuan personal knowledge management system prior to version 3.6.2. The Siyuan kernel exposes an unauthenticated file-serving endpoint under the path `/appearance/*filepath`. Due to improper path sanitization, attackers can exploit this endpoint to perform directory traversal attacks, allowing them to read arbitrary files accessible to the server process. This endpoint explicitly excludes authentication checks, meaning attackers do not need valid credentials to exploit this issue. The vulnerability was fixed in version 3.6.2.

Impact Analysis

This vulnerability can allow an attacker to read arbitrary files on the server running the SiYuan system without authentication. This could lead to exposure of sensitive information stored on the server, including configuration files, user data, or other confidential files accessible to the server process. Since the attacker does not need valid credentials, the risk of unauthorized data disclosure is significant.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

To mitigate this vulnerability, upgrade SiYuan to version 3.6.2 or later, where the issue has been fixed.

Since the vulnerability involves an unauthenticated file-serving endpoint allowing directory traversal, avoid exposing the affected endpoint (/appearance/*filepath) to untrusted networks until the upgrade is applied.

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