CVE-2026-73056
SiYuan kernel before 3.7.4 Unthrottled Brute-Force via API Token
- State
- Published
- Severity
- 9.3 Critical
- Published
- Aug 16, 2026
- Updated
- Aug 17, 2026
- Reserved
- Aug 10, 2026
Description
SiYuan kernel versions before 3.7.4 contain an improper restriction of excessive authentication attempts vulnerability in the CheckAuth() middleware. The middleware accepts the API token (Conf.Api.Token) via an Authorization header (Token/Bearer) or a ?token= query parameter, and neither path is protected by the application's CAPTCHA/lockout mechanism (NeedCaptcha/WrongAuthCount). As a result, an unauthenticated remote attacker can perform unlimited automated guesses of the API token, particularly when a short or weak custom token has been configured, and upon success gains full RoleAdministrator access enabling arbitrary file operations and SQL queries.
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-m6w6-p7pc-fpg2)vendor-advisory
- VulnCheck Advisory: SiYuan kernel before 3.7.4 Unthrottled Brute-Force via API Tokenthird-party-advisory
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