SiYuan: A parser differential between the WebSocket keepalive exemption and the session quarantine allows unauthenticated access to the broadcast event stream

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

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.

[ Fixes ]Fixes and patches

• github.com/siyuan-note/siyuan/kernel 0.0.0-20260731131820-67bc300b6ea6Fixed version · GitHub Advisories · go package github.com/siyuan-note/siyuan/kernel: upgrade to 0.0.0-20260731131820-67bc300b6ea6 or later (affected < 0.0.0-20260731131820-67bc300b6ea6)

[ Packages ]Affected open-source packages

• github.com/siyuan-note/siyuan/kernel goAffected < 0.0.0-20260731131820-67bc300b6ea6 · fixed in 0.0.0-20260731131820-67bc300b6ea6 · GHSA-c8w8-3pqp-wr83

[ References ]References

• github.com/siyuan-note/siyuan/security/advisories/GHSA-c8w8-3pqp-wr83vendor-advisory
• www.vulncheck.com/advisories/siyuan-before-authentication-bypass-via-websocketthird-party-advisory