Unauthenticated administrator access via loopback-trusted requests
Published Aug 12, 2026 · Updated Aug 12, 2026
Authentication bypass in SiYuan before 3.7.4 allows local users to access selected administrator endpoints without credentials. CheckAuth assigns RoleAdministrator when RemoteAddr is 127.0.0.1 before enforcing the access auth code for system, asset, and export routes. Network exploitation requires a fixed-port proxy bound to a network interface to relay requests over loopback; that unverified chain exposes workspace data reads and service shutdown, not the full administrator API.
Summary
What happened
Authentication bypass in SiYuan before 3.7.4 allows local users to access selected administrator endpoints without credentials. CheckAuth assigns RoleAdministrator when RemoteAddr is 127.0.0.1 before enforcing the access auth code for system, asset, and export routes. Network exploitation requires a fixed-port proxy bound to a network interface to relay requests over loopback; that unverified chain exposes workspace data reads and service shutdown, not the full administrator API.
The record
- CVE
- CVE-2026-72809
- Published
- Aug 12, 2026
- Updated
- Aug 12, 2026
- Vendor
- SiYuan Note
- Product
- SiYuan
- Classifications
- CWE-290, CAPEC-21
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 12, 2026CVE publishedPublication date reported by the CVE source.
- Aug 12, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <3.7.4
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Loopback getWorkspaceInfo differential proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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