CVE-2026-72809

Summary

SiYuan versions <= v3.7.2 (patched in v3.7.4) contain an authentication bypass vulnerability in the kernel's CheckAuth function, which grants the administrator role (RoleAdministrator) to any request whose RemoteAddr is loopback (127.0.0.1) for a specific set of endpoints (including /api/system/exit, getNetwork, getWorkspaceInfo, /assets/, and /export/). These localhost bypasses sit outside the access auth code gate, so they apply even when an access auth code is configured. Because the fixed-port reverse proxy forwards requests to the kernel over loopback without injecting an authentication token and does not configure trusted proxies, a request forwarded through this proxy reaches the kernel with RemoteAddr = 127.0.0.1. If the fixed-port proxy is bound to a network interface, this could allow a remote unauthenticated attacker to obtain admin access on the affected endpoints; however, per the advisory this remote forwarding behavior was established only by code inspection and was not reproduced end-to-end.

Affected Software

Weaknesses

• CWE-290: Authentication Bypass by Spoofing

References

• https://github.com/siyuan-note/siyuan/security/advisories/GHSA-3mp7-4rh5-jrv9
• https://www.vulncheck.com/advisories/siyuan-before-authentication-bypass-via-localhost-trust

• ←Previous
• Next→