Path Traversal in B3log Siyuan

CVE-2026-33476

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.

Vulnerability class: Path Traversal (Directory Traversal)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.031 (87.1th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 87th percentile — 87.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-33476: held from 0.033 to 0.031.

EPSS over last 30 days · oldest: 0.033 · newest: 0.031 · change: -0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-33476?
CVE-2026-33476 is a high-severity vulnerability in B3log Siyuan, classified under Path Traversal. CVSS score: 7.5/10. Published 2026-03-20.
How severe is CVE-2026-33476?
High severity. CVSS v3 base score is 7.5 out of 10.