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TI-2026-64802 Aliases CVE-2026-100642GHSA-8r4c-c246-mwjc

SiYuan v2.1.0 before v3.8.4 Cross-Site Request Forgery via CheckAuth

Priority HIGH 65CWE-346Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-346.

Summary

SiYuan versions from v2.1.0 before v3.8.4 contain a cross-site request forgery vulnerability in the CheckAuth lock-screen pass-through branch that grants administrator access to loopback requests without validating Origin headers. Attackers can craft malicious web pages that force victims to terminate the kernel process, read workspace configuration and proxy settings, and trigger administrative actions via zero-credential cross-origin requests from the victim's browser.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00127 2nd percentileScored 2026-11-07
Fix Fixed siyuan (siyuan-note): 3.8.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

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-notesiyuan2.1.0 to before 3.8.43.8.4Patch availableCNA
  • siyuan Vendorsiyuan-note Affected 2.1.0 to before 3.8.4 Fixed in 3.8.4 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 3.8.4

Fixed in the same release

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

  • Release ·

    siyuan-note siyuan 3.8.4

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

    Other records, highest priority first

    • TI-2026-64804 SiYuan before v3.8.4 SQL Injection via dailyNoteSavePathPriority HIGH 77
    • TI-2026-64806 SiYuan before v3.8.4 Authentication Bypass via Missing Origin HeaderPriority HIGH 72
    • TI-2026-64805 SiYuan 3.7.0 before 3.8.4 Stored XSS via Gallery KanbanPriority HIGH 72
    Show all 14 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-100642
  2. 2026-10-03 Alias added: GHSA-8r4c-c246-mwjc

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