CVE-2026-73056: Improper Restriction of Excessive Authentication Attempts in siyuan-note siyuan
SiYuan Note versions prior to 3.7.4 have a vulnerability in the CheckAuth() middleware that allows unlimited automated guesses of the API token via the Authorization header or token query parameter. This bypasses CAPTCHA and lockout protections, enabling unauthenticated attackers to gain full administrator access. The vulnerability is critical with a CVSS score of 9.3.
AI Analysis
Technical Summary
SiYuan Note 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 via an Authorization header or a token query parameter, neither of which is protected by CAPTCHA or lockout mechanisms. This allows unauthenticated remote attackers to perform unlimited automated guesses of the API token. If the token is short or weak, successful guessing grants full RoleAdministrator access, enabling arbitrary file operations and SQL queries.
Potential Impact
An unauthenticated attacker can perform unlimited automated guesses of the API token due to lack of rate limiting or CAPTCHA protections on both Authorization header and token query parameter paths. Successful exploitation results in full RoleAdministrator privileges, allowing arbitrary file operations and SQL queries, which can lead to complete system compromise.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should ensure that API tokens are strong and complex to reduce the risk of successful guessing. Monitor vendor communications for updates regarding official patches or mitigations.
CVE-2026-73056: Improper Restriction of Excessive Authentication Attempts in siyuan-note siyuan
Description
SiYuan Note versions prior to 3.7.4 have a vulnerability in the CheckAuth() middleware that allows unlimited automated guesses of the API token via the Authorization header or token query parameter. This bypasses CAPTCHA and lockout protections, enabling unauthenticated attackers to gain full administrator access. The vulnerability is critical with a CVSS score of 9.3.
CVSS v4.0
Score 9.3critical
Affected software
pkg:github/siyuan-note/siyuanRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
SiYuan Note 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 via an Authorization header or a token query parameter, neither of which is protected by CAPTCHA or lockout mechanisms. This allows unauthenticated remote attackers to perform unlimited automated guesses of the API token. If the token is short or weak, successful guessing grants full RoleAdministrator access, enabling arbitrary file operations and SQL queries.
Potential Impact
An unauthenticated attacker can perform unlimited automated guesses of the API token due to lack of rate limiting or CAPTCHA protections on both Authorization header and token query parameter paths. Successful exploitation results in full RoleAdministrator privileges, allowing arbitrary file operations and SQL queries, which can lead to complete system compromise.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, users should ensure that API tokens are strong and complex to reduce the risk of successful guessing. Monitor vendor communications for updates regarding official patches or mitigations.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-08-10T19:10:18.101Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a81ba98bf8831d539226fa0
Added to database: 08/16/2026, 13:26:48 UTC
Last enriched: 08/24/2026, 13:22:31 UTC
Last updated: 09/06/2026, 02:30:34 UTC
Views: 91
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