Vulnerability · CVE-2026-40322
SiYuan is an open-source personal knowledge management system.
Published Apr 16, 2026 · catalog updated Jun 17, 2026 · SiYuan is an open-source
Check if you run it
No confirmed exploitation is on record for CVE-2026-40322. EPSS is 0.53%. Act only if a listed version of SiYuan is an open-source is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (SiYuan is an open-source).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Critical9.0
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.53%
- Remediation
- Advisory link
- Affected products
- cpe b3log/siyuan
SiYuan is an open-source personal knowledge management system. In versions 3.6.3 and below, Mermaid diagrams are rendered with securityLevel set to "loose", and the resulting SVG is injected into the DOM via innerHTML. This allows attacker-controlled javascript: URLs in Mermaid code blocks to survive into the rendered output. On desktop builds using Electron, windows are created with nodeIntegration enabled and contextIsolation disabled, escalating the stored XSS to arbitrary code execution when a victim opens a note containing a malicious Mermaid block and clicks the rendered diagram node. This issue has been fixed in version 3.6.4.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe b3log/siyuanversion unspecified
How to fix CVE-2026-40322
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-40322. EPSS is 0.53%. Act only if a listed version of SiYuan is an open-source is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-79: Cross-site Scripting (XSS); CWE-94: Code Injection. EPSS 0.53%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Apr 16, 2026 · NIST NVD
Detected
SiYuan is an open-source personal knowledge management system. In versions 3.6.3 and below, Mermaid diagrams are rendered with securityLevel set to "loose", and the resulting SVG is injected into the DOM via innerHTML. This allows attacker-controlled javascript: URLs in Mermaid code blocks to survive into the rendered output. On desktop builds using Electron, windows are created with nodeIntegrati
Jun 17, 2026 · NIST NVD
Updated
SiYuan is an open-source personal knowledge management system. In versions 3.6.3 and below, Mermaid diagrams are rendered with securityLevel set to "loose", and the resulting SVG is injected into the DOM via innerHTML. This allows attacker-controlled javascript: URLs in Mermaid code blocks to survive into the rendered output. On desktop builds using Electron, windows are created with nodeIntegrati
Sources
- CVE.orgVulnerability recordCVE-2026-40322
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-40322
30-day exploitation probability 0.5%
first.org - NIST NVDVulnerability recordCVE-2026-40322
SiYuan is an open-source personal knowledge management system. In versions 3.6.3 and below, Mermaid diagrams are rendered with securityLevel set to "loose", and the resulting SVG is injected into the DOM via innerHTML. This allows attacker-controlled javascript: URLs in Mermaid c
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.