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)
EPSS: 0.033 (87.1th percentile) — read the EPSS interpretation.
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.
Affected products
- B3log Siyuan
- Siyuan-note Siyuan — versions < 3.6.2
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
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.