CVE-2026-73056

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.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-m6w6-p7pc-fpg2
https://www.vulncheck.com/advisories/siyuan-kernel-before-unthrottled-brute-force-via-api-token
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-m6w6-p7pc-fpg2

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-16 14:16

Updated : 2026-08-26 17:04

NVD link : CVE-2026-73056

Mitre link : CVE-2026-73056

CVE.ORG link : CVE-2026-73056

JSON object : View

Products Affected

No product.

CWE

CWE-307

Improper Restriction of Excessive Authentication Attempts

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