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TI-2026-24364 Aliases CVE-2026-31809GHSA-pmc9-f5qr-2pcr

SiYuan has a SVG Sanitizer Bypass via Whitespace in `javascript:` URI — Unauthenticated XSS

Priority MEDIUM 62CWE-79Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.

Summary

SiYuan is a personal knowledge management system. Prior to 3.5.10, SiYuan's SVG sanitizer (SanitizeSVG) checks href attributes for the javascript: prefix using strings.HasPrefix(). However, inserting ASCII tab (	), newline (
), or carriage return (
) characters inside the javascript: string bypasses this prefix check. Browsers strip these characters per the WHATWG URL specification before parsing the URL scheme, so the JavaScript still executes. This allows an attacker to inject executable JavaScript into the unauthenticated /api/icon/getDynamicIcon endpoint, creating a reflected XSS. This is a second bypass of the fix for CVE-2026-29183 (fixed in v3.5.9). This vulnerability is fixed in 3.5.10.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00562 46th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed siyuan (siyuan-note): 3.5.10github.com/siyuan-note/siyuan/kernel (Go): 0.0.0-20260310025236-297bd526708f

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-notesiyuanbefore 3.5.103.5.10Patch availableCNA
—github.com/siyuan-note/siyuan/kernel (Go)before 0.0.0-20260310025236-297bd526708f0.0.0-20260310025236-297bd526708fPatch availableGHSA-pmc9-f5qr-2pcr
  • siyuan Vendorsiyuan-note Affected before 3.5.10 Fixed in 3.5.10 Patch available CNA
  • github.com/siyuan-note/siyuan/kernel (Go) Vendor— Affected before 0.0.0-20260310025236-297bd526708f Fixed in 0.0.0-20260310025236-297bd526708f Patch available GHSA-pmc9-f5qr-2pcr

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*before 3.5.10Vulnerablesiyuan-note
  • cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:* Versions before 3.5.10 Vulnerable ·siyuan-note

Remediation

  • Fix · CNA siyuan (siyuan-note) Fixed in 3.5.10
  • Fix · GHSA-pmc9-f5qr-2pcr github.com/siyuan-note/siyuan/kernel (Go) Fixed in 0.0.0-20260310025236-297bd526708f Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-31809
  2. 2026-10-03 Alias added: GHSA-pmc9-f5qr-2pcr

References

Exploit 1

Advisory 1

Other 2

  • 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
  • TI-2024-35827 A SQL injection vulnerability was discovered in Siyuan 3.1.11 in /getHistoryItems. CVSS 3.1CRITICAL 9.8
  • TI-2024-35826 A SQL injection vulnerability has been identified in Siyuan 3.1.11 via the ids array parameter in /batchGetBlockAttrs. CVSS 3.1CRITICAL 9.8
  • TI-2024-35825 A SQL injection vulnerability has been identified in Siyuan 3.1.11 via the id parameter at /getAssetContent. CVSS 3.1CRITICAL 9.8
  • TI-2024-35824 A SQL injection vulnerability has been identified in Siyuan 3.1.11 via the notebook parameter in /searchHistory. CVSS 3.1CRITICAL 9.8
See all 54 →

Sources

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