by Kastro
Paper/Archive/CVE-2026-73046

CVE-2026-73046

siyuan-note siyuan — SiYuan before v3.7.4 Authentication Bypass via HTTP Basic Auth

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 before v3.7.4 improperly restricts excessive authentication attempts in the CheckAuth() middleware. The HTTP Basic Authentication branch, which guards nearly the entire /api/* surface, accepts the workspace access code (Conf.AccessAuthCode) as the Basic Auth password but never consults the CAPTCHA/lockout gate or increments the failure counter used by the cookie/session login path. This allows unauthenticated remote attackers to brute-force the admin access code with unlimited automated requests and obtain full RoleAdministrator access to the kernel. A secondary weakness exists because the access code is compared using a non-constant-time string comparison.

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-w3xh-mmmh-r54vwriteupvulncheck.com/advisories/siyuan-before-authentication-bypass-via-http-basic-auth