CVE-2026-40259

High

Description

SiYuan is an open-source personal knowledge management system. In versions 3.6.3 and below, the /api/av/removeUnusedAttributeView endpoint is protected only by generic authentication that accepts publish-service RoleReader tokens. The handler passes a caller-controlled id directly to a model function that unconditionally deletes the corresponding attribute view file from the workspace without verifying that the caller has write privileges or that the target attribute view is actually unused. An authenticated publish-service reader can permanently delete arbitrary attribute view definitions by extracting publicly exposed data-av-id values from published content, causing breakage of database views and workspace rendering until manually restored. This issue has been fixed in version 3.6.4.

SeverityHigh
CVSS8.1
Exploit probability—
ProductB3log Siyuan
PublishedApr 16, 2026
First seenApr 16, 2026
Weakness typeCWE-285CWE-285

How to fix

Update
  • b3log siyuan3.6.4 or later
  • github.com/siyuan-note/siyuan/kernel0.0.0-20260407035653-2f416e5253f1 or later

Affected products

ProductAffected versionsFixed in
b3log siyuanv < 3.6.43.6.4
github.com/siyuan-note/siyuan/kernelGov < 0.0.0-20260407035653-2f416e5253f10.0.0-20260407035653-2f416e5253f1

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CVE-2026-40259 · B3log Siyuan · Dark Radar