CVE-2026-77086: siyuan-note siyuan Path Traversal

Vulnerability summary

CVE-2026-77086 is a critical (CVSS 9.4) Path Traversal vulnerability in siyuan-note siyuan. EPSS estimates a 1.03% chance of exploitation in the next 30 days, higher than 63.2% of scored vulnerabilities.

Timeline

1. 21-08-2026
   PublishedVulnerability first disclosed.
2. 01-10-2026
   Last modifiedVulnerability information updated.

Description

SiYuan before v3.7.4 fails to validate the packageName parameter in Bazaar install and uninstall endpoints, allowing authenticated administrators to perform path traversal via directory traversal sequences. Attackers with admin access can write arbitrary files to any location via install operations or recursively delete directories via uninstall operations by supplying crafted packageName values.

• 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.