TI-2026-80187 Aliases CVE-2026-116169 GHSA-mqcm-q7hm-v37p

SiYuan Stored XSS via KaTeX \href in Math Blocks

MEDIUM 56CWE-79Published 2026-10-25 · Updated 2026-10-29

Key facts

Attack vector: Network
Privileges required: Low
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. Impact type from CWE-79.

Summary

SiYuan from 2.10.0 before 3.8.7 contains a stored cross-site scripting flaw (CWE-79) in math block rendering. Users with edit permission can place javascript: URLs in math block content rendered with KaTeX trust enabled, and the link runs script in the application origin when a reader clicks it. Exploitation requires a reader to click the stored link. CISA's SSVC assessment lists exploitation as proof of concept only, and the CVE is not in KEV.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

SiYuan from 2.10.0 before 3.8.7 contains a stored cross-site scripting vulnerability that allows users with edit permission to inject script by placing javascript: URLs in math block content rendered with KaTeX trust enabled. Attackers can store \href, \url, or \includegraphics payloads that mathRender assigns via innerHTML, executing script in the application origin when a reader clicks the rendered link.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00205 10th percentileScored 2026-11-07

Fix Fixed siyuan (siyuan-note): 3.8.7

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

Vendor	Product	Affected versions	Fixed in	Status	Source
siyuan-note	siyuan	2.10.0 to before 3.8.7	3.8.7	Patch available	CNA

siyuan Vendorsiyuan-note Affected 2.10.0 to before 3.8.7 Fixed in 3.8.7 Patch available CNA

CPE names Threatist (inferred) · 1

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

CPE	Versions	Role	Vendor
cpe:2.3:a:b3log:siyuan::::::::	—	—	siyuan-note

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

Remediation

Upgrade SiYuan to version 3.8.7 or later, which fixes the flaw.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Fix · CNA siyuan (siyuan-note) Fixed in 3.8.7

Fixed in the same release

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

Release · 2026-10-25
siyuan-note siyuan 3.8.7
6 records Highest priority Priority HIGH 1 HIGH, 3 MEDIUM, 2 LOW
Other records, highest priority first
- TI-2026-80184 Cleartext transmission in SiYuan exposes login and session cookiesPriority HIGH 68
- TI-2026-80188 SQL injection in SiYuan history search exposes history.dbPriority MEDIUM 64
- TI-2026-80186 Path traversal in SiYuan MCP asset tool lets attackers read local filesPriority MEDIUM 64
Show all 6 records →

Timeline

2026-10-25 Threatist record created from CVE-2026-116169
2026-10-27 Alias added: GHSA-mqcm-q7hm-v37p
2026-10-29 CISA SSVC decision points changed
2026-10-29 Priority changed: LOW → MEDIUM

References

Advisory 1

GitHub Security Advisory (GHSA-hhvq-jqv9-pgjq)

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