CVE-2026-40318: SiYuan is an open-source personal knowledge management system

Q: How do I fix CVE-2026-40318?

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

Q: Is CVE-2026-40318 being exploited?

CVE-2026-40318 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-2026-40318 affect?

CVE-2026-40318 affects siyuan. Severity is high (CVSS 8.5). SiYuan is an open-source personal knowledge management system. In versions 3.6.3 and prior, the /api/av/removeUnusedAttributeView endpoint constructs a filesystem path using the user-controlled id parameter without validation or path bounda

Routine

HIGH 8.5UPGRADE

CVE-2026-40318 is a high-severity flaw (CVSS 8.5) 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 3.6.3 and prior, the /api/av/removeUnusedAttributeView endpoint constructs a filesystem path using the user-controlled id parameter without validation or path boundary enforcement. An attacker can inject path traversal sequences such as ../ into the id value to escape the intended directory and delete arbitrary .json files on the server, including global configuration file

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 79%)
CISA exploited list	No
Weakness	CWE-24
Published	2026-04-16
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

2026-04-16 23:16 UTCPublished CVE record published
2026-06-17 10:45 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-2026-40318?

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

Is CVE-2026-40318 being exploited?

CVE-2026-40318 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-2026-40318 affect?

CVE-2026-40318 affects siyuan. Severity is high (CVSS 8.5). SiYuan is an open-source personal knowledge management system. In versions 3.6.3 and prior, the /api/av/removeUnusedAttributeView endpoint constructs a filesystem path using the user-controlled id parameter without validation or path bounda

How urgent is CVE-2026-40318?

Priority 35/100. High severity

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-2026-40259 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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