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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
siyuan-note siyuan unaffected
Version Status Constraints
0 affected < 3.7.4
3.7.4 unaffected —

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Project Subscriptions

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Advisories

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

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

Sun, 16 Aug 2026 13:30:00 +0000

Type Values Removed Values Added
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.
Title SiYuan kernel before 3.7.4 Unthrottled Brute-Force via API Token
First Time appeared B3log
B3log siyuan
Weaknesses CWE-307
CPEs cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*
Vendors & Products B3log
B3log siyuan
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-16T13:14:04.660Z

Reserved: 2026-08-10T19:10:18.101Z

Link: CVE-2026-73056

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-16T14:16:55.083

Modified: 2026-08-16T14:16:55.083

Link: CVE-2026-73056

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-16T14:45:04Z

Weaknesses