by Kastro
Paper/Archive/CVE-2026-73056

CVE-2026-73056

siyuan-note siyuan — SiYuan kernel before 3.7.4 Unthrottled Brute-Force via API Token

EPSS 0.8%public exploitCVSS 9.8
critical.is priorityof 100
51
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 56.3.563 × 2011.3Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
siyuan< 3.7.43.7.4CNA

Scores by source

VulnCheck (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
VulnCheck (CNA)9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CISA ADPSSVCExploitation: poc · Automatable: yes · Technical impact: total

References

exploitgithub.com/siyuan-note/siyuan/security/advisories/GHSA-m6w6-p7pc-fpg2writeupvulncheck.com/advisories/siyuan-kernel-before-unthrottled-brute-force-via-api-token