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TI-2026-38998 Aliases CVE-2026-54067GHSA-mvjr-vv3c-w4qv

SiYuan: Stored XSS to RCE via CSS-snippet <style> breakout in renderSnippet()

Priority HIGH 76CWE-1188Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Cross-site scripting
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.

Summary

SiYuan is an open-source personal knowledge management system. Prior to 3.7.0, CSS snippet body containing </style> breaks out of its surrounding <style> tag when renderSnippet() interpolates it via insertAdjacentHTML. A payload like runs arbitrary JavaScript in the renderer. On Electron desktop builds the renderer runs with nodeIntegration:true, so require('child_process') is reachable from the injected handler and the XSS chains to host RCE. Snippets sync via the workspace repository, so an attacker with write access to any synced workspace plants the payload once and it fires on every device that pulls. The bug also bypasses the user's enabledCSS / enabledJS separation. A user who turned enabledJS off was making a deliberate call not to run untrusted JavaScript; the CSS path runs it anyway. This vulnerability is fixed in 3.7.0.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00381 32nd percentileScored 2026-11-07
Fix Fixed siyuan (siyuan-note): 3.7.0github.com/siyuan-note/siyuan/kernel (Go): 0.0.0-20260628153353-2d5d72223df4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
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 3.7.03.7.0Patch availableCNA
—github.com/siyuan-note/siyuan/kernel (Go)before 0.0.0-20260628153353-2d5d72223df40.0.0-20260628153353-2d5d72223df4Patch availableGHSA-mvjr-vv3c-w4qv
  • siyuan Vendorsiyuan-note Affected before 3.7.0 Fixed in 3.7.0 Patch available CNA
  • github.com/siyuan-note/siyuan/kernel (Go) Vendor— Affected before 0.0.0-20260628153353-2d5d72223df4 Fixed in 0.0.0-20260628153353-2d5d72223df4 Patch available GHSA-mvjr-vv3c-w4qv

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 3.7.0
  • Fix · GHSA-mvjr-vv3c-w4qv github.com/siyuan-note/siyuan/kernel (Go) Fixed in 0.0.0-20260628153353-2d5d72223df4 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-54067
  2. 2026-10-03 Alias added: GHSA-mvjr-vv3c-w4qv

References

Advisory 1

Other 2

  • 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