CVE-2026-40107: SiYuan is a personal knowledge management system

Q: How do I fix CVE-2026-40107?

siyuan: upgrade to 3.6.4. Exact commands for each OS are on this page.

Q: Is CVE-2026-40107 being exploited?

CVE-2026-40107 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-40107 affect?

CVE-2026-40107 affects siyuan. Severity is medium (CVSS 6.5). SiYuan is a personal knowledge management system. Prior to 3.6.4, SiYuan configures Mermaid.js with securityLevel: "loose" and htmlLabels: true. In this mode, tags with src attributes survive Mermaid's internal DOMPurify and land in S

Routine

MEDIUM 6.5UPGRADE

CVE-2026-40107 is a medium-severity flaw (CVSS 6.5) affecting siyuan. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

SiYuan is a personal knowledge management system. Prior to 3.6.4, SiYuan configures Mermaid.js with securityLevel: "loose" and htmlLabels: true. In this mode, <img> tags with src attributes survive Mermaid's internal DOMPurify and land in SVG <foreignObject> blocks. The SVG is injected via innerHTML with no secondary sanitization. When a victim opens a note containing a malicious Mermaid diagram, the Electron client fetches the URL. On Windows, a

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.3% (top 77%)
CISA exploited list	No
Weakness	CWE-918
Published	2026-04-09
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: b3log

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-09 21:16 UTCPublished CVE record published
2026-06-17 10:44 UTCUpdated Record last modified

b3log siyuan UPGRADE

Affected: < 3.6.4

Fixed in: 3.6.4

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy siyuan || rpm -q siyuan || siyuan --version

2. UPGRADE to 3.6.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade siyuan

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade siyuan

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-40107?

siyuan: upgrade to 3.6.4. Exact commands for each OS are on this page.

Is CVE-2026-40107 being exploited?

CVE-2026-40107 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-40107 affect?

CVE-2026-40107 affects siyuan. Severity is medium (CVSS 6.5). SiYuan is a personal knowledge management system. Prior to 3.6.4, SiYuan configures Mermaid.js with securityLevel: "loose" and htmlLabels: true. In this mode, <img> tags with src attributes survive Mermaid's internal DOMPurify and land in S

How urgent is CVE-2026-40107?

Priority 34/100. Public exploit reference

Software pages

Windows vulnerabilities · Electron vulnerabilities

Related CVEs

CVE-2026-39846 CRITICAL 9.0 UPGRADE SiYuan is a personal knowledge management system
CVE-2026-40922 MEDIUM 5.4 UPGRADE SiYuan is an open-source personal knowledge management system
CVE-2026-40322 CRITICAL 9.0 UPGRADE SiYuan is an open-source personal knowledge management system
CVE-2026-40318 HIGH 8.5 UPGRADE SiYuan is an open-source personal knowledge management system
CVE-2026-40259 HIGH 8.1 UPGRADE SiYuan is an open-source personal knowledge management system

References

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