๐Ÿ” CVE Alert

CVE-2026-73046

CRITICAL 9.8

SiYuan before v3.7.4 Authentication Bypass via HTTP Basic Auth

CVSS Score
9.8
EPSS Score
0.0%
EPSS Percentile
0th

SiYuan before v3.7.4 improperly restricts excessive authentication attempts in the CheckAuth() middleware. The HTTP Basic Authentication branch, which guards nearly the entire /api/* surface, accepts the workspace access code (Conf.AccessAuthCode) as the Basic Auth password but never consults the CAPTCHA/lockout gate or increments the failure counter used by the cookie/session login path. This allows unauthenticated remote attackers to brute-force the admin access code with unlimited automated requests and obtain full RoleAdministrator access to the kernel. A secondary weakness exists because the access code is compared using a non-constant-time string comparison.

CWE CWE-307
Vendor siyuan-note
Product siyuan
Published Aug 15, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Affected Versions

siyuan-note / siyuan
0 < 3.7.4

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/siyuan-note/siyuan/security/advisories/GHSA-w3xh-mmmh-r54v vulncheck.com: https://www.vulncheck.com/advisories/siyuan-before-authentication-bypass-via-http-basic-auth

Credits

๐Ÿ” alham-rizvi