CVE-2026-73056

Name of the Vulnerable Software and Affected Versions SiYuan kernel versions prior to 3.7.4

Description An improper restriction of excessive authentication attempts exists in the CheckAuth() middleware. The middleware accepts the Conf.Api.Token API token through an Authorization header (Token/Bearer) or a token query parameter. Neither of these paths is protected by the application's CAPTCHA or lockout mechanisms, specifically NeedCaptcha and WrongAuthCount. This allows an unauthenticated remote attacker to perform unlimited automated guesses of the API token. If a short or weak custom token is used, a successful guess grants full RoleAdministrator access, allowing for arbitrary SQL queries and file operations.

Recommendations Update SiYuan kernel to version 3.7.4 or later.