Read the docs
TI-2026-51255 Aliases CVE-2026-73046GHSA-84q8-8mw3-429h

SiYuan before v3.7.4 Authentication Bypass via HTTP Basic Auth

Priority HIGH 81CWE-307Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-307.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.0079 56th percentileScored 2026-11-07
Fix Fixed siyuan (siyuan-note): 3.7.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
siyuan-notesiyuanbefore 3.7.43.7.4Patch availableCNA
  • siyuan Vendorsiyuan-note Affected before 3.7.4 Fixed in 3.7.4 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*——siyuan-note
  • cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:* Versions — — ·siyuan-note

Remediation

  • Fix · CNA siyuan (siyuan-note) Fixed in 3.7.4

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    siyuan-note siyuan 3.7.4

    11 records Highest priority Priority HIGH 8 HIGH, 2 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-51263 SiYuan before v3.7.4 Authentication Bypass via WebSocketPriority HIGH 77
    • TI-2026-51262 SiYuan before v3.7.4 Cross-Site Scripting via unicode2EmojiPriority HIGH 76
    • TI-2026-51261 SiYuan before v3.7.4 Stored XSS via Attribute-View Field NamesPriority HIGH 76
    Show all 11 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-73046
  2. 2026-10-03 Alias added: GHSA-84q8-8mw3-429h

References

Advisory 1

  • TI-2026-48492 SiYuan before v3.7.3 SQL Injection via searchDocs CVSS 4.0CRITICAL 9.9
  • TI-2026-48491 SiYuan before v3.7.3 SQL Injection via searchEmbedBlock CVSS 4.0CRITICAL 9.9
  • TI-2026-48490 SiYuan before v3.7.3 SQL Injection via fullTextSearchAssetContent CVSS 4.0CRITICAL 9.9
  • TI-2026-47010 SiYuan before v3.7.2 Unauthenticated Administrator Takeover via MCP CVSS 4.0CRITICAL 10.0
  • TI-2026-26050 SiYuan has directory traversal within its publishing service CVSS 3.1CRITICAL 9.8
  • TI-2026-25256 SiYuan: Authorization Bypass Allows Arbitrary SQL Execution via Search API CVSS 3.1CRITICAL 9.8
See all 242 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences