CVE-2026-73056
CriticalCVSS 9.8Summary
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 via an Authorization header or ?token= query parameter, and neither path is protected by CAPTCHA/lockout. An unauthenticated remote attacker can perform unlimited automated guesses of the API token, especially when a short or weak custom token is configured, and upon success gains full RoleAdministrator access enabling arbitrary file operations and SQL queries.
Risk Assessment
Risk of full compromise of the SiYuan application, including data access and arbitrary operations, potentially leading to severe security breaches.
Recommendation
Update SiYuan to version 3.7.4 or later and configure a strong, long API token.
Original NVD description (English source)
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.