CVE-2026-40922: SiYuan is an open-source personal knowledge management system

Routine

MEDIUM 5.4UPGRADE

CVE-2026-40922 is a medium-severity flaw (CVSS 5.4) affecting siyuan. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 attrib

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.3% (top 82%)
CISA exploited list	No
Weakness	CWE-79
Published	2026-04-17
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

2026-04-17 01:17 UTCPublished CVE record published
2026-06-17 10:45 UTCUpdated Record last modified

b3log siyuan UPGRADE

Affected: >= 3.6.1 and < 3.6.4

Fixed in: 3.6.4

Safe to downgrade to: a release before 3.6.1

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.

3. If no update is available yet, DOWNGRADE to a release before 3.6.1 (Debian / Ubuntu)

apt-cache madison siyuan sudo apt install siyuan=<VERSION_BEFORE_3.6.1> sudo apt-mark hold siyuan

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list siyuan sudo dnf downgrade siyuan-<VERSION_BEFORE_3.6.1> sudo dnf versionlock add siyuan

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2026-40922?

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

Is CVE-2026-40922 being exploited?

CVE-2026-40922 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-2026-40922 affect?

CVE-2026-40922 affects siyuan. Severity is medium (CVSS 5.4). 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 b

How urgent is CVE-2026-40922?

Priority 28/100. Public exploit reference

Related CVEs

CVE-2026-39846 CRITICAL 9.0 UPGRADE SiYuan is a 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
CVE-2026-40107 MEDIUM 6.5 UPGRADE SiYuan is a personal knowledge management system

References

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