CVE-2026-33476: b3log siyuan Path Traversal

Vulnerability summary

CVE-2026-33476 is a high (CVSS 7.5) Path Traversal vulnerability in b3log siyuan. EPSS estimates a 3.06% chance of exploitation in the next 30 days, higher than 87.4% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 20-03-2026
   PublishedVulnerability first disclosed.
2. 23-03-2026
   Last modifiedVulnerability information updated.

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.

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')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.
• CWE-73External Control of File Name or PathThe product allows user input to control or influence paths or file names that are used in filesystem operations.