CVE-2026-73046
SiYuan before v3.7.4 Authentication Bypass via HTTP Basic Auth
- State
- Published
- Severity
- 9.3 Critical
- Published
- Aug 15, 2026
- Updated
- Aug 17, 2026
- Reserved
- Aug 10, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 9.3 Critical | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | VulnCheck |
Weaknesses
- CWE-307 Improper Restriction of Excessive Authentication Attempts
Affected Products
| Product | Versions |
|---|---|
siyuansiyuan-note |
|
References
- GitHub Security Advisory (GHSA-w3xh-mmmh-r54v)vendor-advisory
- VulnCheck Advisory: SiYuan before v3.7.4 Authentication Bypass via HTTP Basic Auththird-party-advisory
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