TI-2026-29576 Aliases CVE-2026-40922 GHSA-8q5w-mmxf-48jg

SiYuan: Incomplete sanitization of bazaar README allows stored XSS via iframe srcdoc (incomplete fix for CVE-2026-33066)

MEDIUM 57CWE-79Published 2026-04-16 · Updated 2026-04-20

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
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 an open-source personal knowledge management system. In versions 3.6.1 through 3.6.3, a prior fix for XSS in bazaar README rendering (incomplete fix for CVE-2026-33066) enabled the Lute HTML sanitizer, but the sanitizer does not block iframe tags, and its URL-prefix blocklist does not effectively filter srcdoc attributes which contain raw HTML rather than URLs. A malicious bazaar package author can include an iframe with a srcdoc attribute containing embedded scripts in their README. When other users view the package in SiYuan's marketplace UI, the payload executes in the Electron context with full application privileges, enabling arbitrary code execution on the user's machine. This issue has been fixed in version 3.6.4.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00261 17th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed siyuan (siyuan-note): 3.6.4github.com/siyuan-note/siyuan/kernel (Go): 0.0.0-20260414013942-62eed37a3263

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	before 3.6.4	3.6.4	Patch available	CNA
—	github.com/siyuan-note/siyuan/kernel (Go)	before 0.0.0-20260414013942-62eed37a3263	0.0.0-20260414013942-62eed37a3263	Patch available	GHSA-8q5w-mmxf-48jg

siyuan Vendorsiyuan-note Affected before 3.6.4 Fixed in 3.6.4 Patch available CNA
github.com/siyuan-note/siyuan/kernel (Go) Vendor— Affected before 0.0.0-20260414013942-62eed37a3263 Fixed in 0.0.0-20260414013942-62eed37a3263 Patch available GHSA-8q5w-mmxf-48jg

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:b3log:siyuan::::::::	3.6.1 to before 3.6.4	Vulnerable	siyuan-note

cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:* Versions 3.6.1 to before 3.6.4 Vulnerable ·siyuan-note

Remediation

Fix · CNA siyuan (siyuan-note) Fixed in 3.6.4
Fix · GHSA-8q5w-mmxf-48jg github.com/siyuan-note/siyuan/kernel (Go) Fixed in 0.0.0-20260414013942-62eed37a3263 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-40922
2026-10-03 Alias added: GHSA-8q5w-mmxf-48jg

References

Exploit 1

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-8q5w-mmxf-48jg

Patch 1

https://github.com/siyuan-note/siyuan/commit/b382f50e1880ed996364509de5a10a72d7409428

Advisory 3

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

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