CVE-2026-40318Public exploitNetwork attack vector

Authenticated JSON-file deletion via unvalidated path construction

Published Apr 16, 2026 · Updated Apr 16, 2026

Path traversal in SiYuan before 3.6.4 allows remote authenticated users to delete arbitrary JSON files through a crafted id value. The /api/av/removeUnusedAttributeView handler passes id into filepath.Join without validating its format or confining the resolved path to data/storage/av. Reachability requires publish service or other valid endpoint access, and successful traversal deletes configuration or workspace metadata and can force recovery.

CVSS severity8.5
High
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in SiYuan before 3.6.4 allows remote authenticated users to delete arbitrary JSON files through a crafted id value. The /api/av/removeUnusedAttributeView handler passes id into filepath.Join without validating its format or confining the resolved path to data/storage/av. Reachability requires publish service or other valid endpoint access, and successful traversal deletes configuration or workspace metadata and can force recovery.

The record

CVE
CVE-2026-40318
Published
Apr 16, 2026
Updated
Apr 16, 2026
Vendor
SiYuan Note
Product
SiYuan
Classifications
CWE-24, T1485
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.6.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

SiYuan Note · SiYuanversion=< 3.6.4

Published CVSS scores

8.5GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-24Path Traversal: '../filedir'
T1485Data Destruction

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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