dbcve.org
SiyuanApplication · B3log

CVE-2026-40318

HIGH · 8.5 CVSS v3.1 Published 2026-04-16
Fix available
A fix is available. Upgrade to 3.6.4 or later.
See remediation →
91/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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 files and workspace metadata. This issue has been fixed in version 3.6.4.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The /api/av/removeUnusedAttributeView endpoint in SiYuan versions 3.6.3 and prior accepts a user-controlled 'id' parameter that is directly used to construct a filesystem path without any validation or path boundary checks. An attacker can inject path traversal sequences (../) in the id parameter to escape the intended directory and delete arbitrary .json files on the server, including global configuration files and workspace metadata.

MitigationUpgrade to SiYuan version 3.6.4 or later, which contains the fix for this path traversal vulnerability. As a defense-in-depth measure, implement strict input validation on the id parameter to reject any path traversal sequences before deploying the upgrade.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
SiyuanApplication
Affected:< 3.6.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check SiYuan version
    Access the SiYuan application and navigate to Settings > About, or check the installation directory for a version file. Compare the displayed version number to the affected range (versions prior to 3.6.4).
    Affected if The installed version is 3.6.3 or lower.
  2. Verify API endpoint accessibility
    Attempt to access the /api/av/removeUnusedAttributeView endpoint by sending a request to your SiYuan server. This can be done via curl or a web request tool. Example: curl -X POST http://localhost:6806/api/av/removeUnusedAttributeView -H 'Content-Type: application/json' -d '{"id":"test"}'
    Affected if The endpoint responds with any JSON response (success or error), indicating it is accessible and the API module is enabled.
  3. Confirm Attribute View feature is in use
    Check if Attribute View (AV) functionality is being used in the workspace. This can be done by looking for .json files in the workspace data folder that correspond to attribute views, or by accessing the SiYuan desktop/web interface and checking for blocks with attribute table views created.
    Affected if Attribute View files exist in the workspace or the feature is actively used.
  4. Test for path traversal vulnerability
    Send a request to the /api/av/removeUnusedAttributeView endpoint with a path traversal payload in the id parameter, such as '{"id":"../../config.json"}'. Observe whether the server processes the request without rejecting path traversal characters.
    Affected if The server accepts path traversal sequences (../) in the id parameter without validation or rejection.

A user is affected if their SiYuan version is 3.6.3 or prior, the API endpoint is accessible, and the id parameter accepts path traversal sequences without sanitization.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.6.4 or later
Fixed in 3.6.4
Interim mitigation

Upgrade to SiYuan version 3.6.4 or later, which contains the fix for this path traversal vulnerability. As a defense-in-depth measure, implement strict input validation on the id parameter to reject any path traversal sequences before deploying the upgrade.

Recommended fix High confidence

3.6.4

  1. Upgrade Siyuan to version 3.6.4 or later to include the patched code that adds validation for the id parameter in the /api/av/removeUnusedAttributeView endpoint

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Siyuan Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-40318 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data