SiYuan up to 3.6.1 /appearance/*filepath path traversal

Summaryinfo

A vulnerability classified as critical has been found in SiYuan up to 3.6.1. This vulnerability affects unknown code of the file /appearance/*filepath. This manipulation causes path traversal. This vulnerability is tracked as CVE-2026-33476. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in SiYuan up to 3.6.1. It has been declared as critical. Affected by this vulnerability is some unknown processing of the file /appearance/*filepath. The manipulation with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect confidentiality. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-33476 since 03/20/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1006 according to MITRE ATT&CK.

Upgrading to version 3.6.2 eliminates this vulnerability. Applying the patch 009bb598b3beccc972aa5f1ed88b3b224326bf2a is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Name

• SiYuan

Version

• 3.6.0
• 3.6.1

License

• open-source

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