VULNERABILITY INTELLIGENCE
CVE-2026-73056
CVSS score9.8 CRITICAL
EPSS probability0.79%
CISA KEVNot currently listed
Published2026-08-16
Last modified2026-08-26
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
Weakness classification
- disclosure@vulncheck.com: CWE-307