Auth bypass in Siyuan-Note Siyuan
CVE-2026-73054
SiYuan versions before v3.7.4 contain an authentication bypass vulnerability in the WebSocket endpoint caused by differential parsing of query parameters between authentication exemption and session quarantine checks. Unauthenticated attackers can craft a malicious WebSocket URI with duplicated query parameters to bypass access auth code validation and receive the live kernel event stream including document identifiers, titles, and operation logs.
Vulnerability class: Broken Authentication
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: 0.005 (43.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 43.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Siyuan-Note Siyuan — versions 0, 3.7.4
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-c8w8-3pqp-wr83 (vendor-advisory)
- www.vulncheck.com/advisories/siyuan-before-authentication-bypass-via-websocket (third-party-advisory)
Frequently asked questions
- What is CVE-2026-73054?
- CVE-2026-73054 is a high-severity vulnerability in Siyuan-Note Siyuan, classified under Improper Authentication. CVSS score: 7.5/10. Published 2026-08-15.
- How severe is CVE-2026-73054?
- High severity. CVSS v3 base score is 7.5 out of 10.