CVE-2026-73056
Medium
Elevated severity or exploit probability.
CVSS base
9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
0.5%
38.4th percentile
CISA KEV
Not listed
Weakness / dates
CWE-307
Published 2026-08-16 · modified 2026-08-26
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.