CVE-2026-40259Public exploitNetwork attack vector

Authenticated attribute view deletion via unchecked API authorization

Published Apr 16, 2026 · Updated Apr 16, 2026

Improper authorization in SiYuan 3.6.3 and earlier allows remote authenticated users to delete attribute view files through the publish API. The removeUnusedAttributeView route accepts a publish-service RoleReader token, forwards the caller-controlled id, and deletes data/storage/av/.json without checking write privileges or whether the view is unused. Exploitation requires enabled publish access and a known data-av-id, and it persistently breaks database views and workspace rendering.

CVSS severity8.1
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper authorization in SiYuan 3.6.3 and earlier allows remote authenticated users to delete attribute view files through the publish API. The removeUnusedAttributeView route accepts a publish-service RoleReader token, forwards the caller-controlled id, and deletes data/storage/av/.json without checking write privileges or whether the view is unused. Exploitation requires enabled publish access and a known data-av-id, and it persistently breaks database views and workspace rendering.

The record

CVE
CVE-2026-40259
Published
Apr 16, 2026
Updated
Apr 16, 2026
Vendor
SiYuan Note
Product
SiYuan
Classifications
CWE-285, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=< 0.0.0-20260407035653-2f416e5253f1
  2. Affected versionversion=< 3.6.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

SiYuan Note · SiYuanversion=< 0.0.0-20260407035653-2f416e5253f1; version=< 3.6.4

Published CVSS scores

8.1GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-285Improper Authorization
T1485Data Destruction

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo