CVE-2026-40318 | SiYuan: Publish Reader Path Traversal Delete via `removeUnusedAttributeView`

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.

Published: 2026-04-16 Last update: 2026-04-20 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-40318 is rated Moderate Risk (40.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.06%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-40318

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-17 — 0.06% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-40318

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.1 4.7 [email protected]

Weakness enumeration for CVE-2026-40318

GitHub Security Advisory for CVE-2026-40318

GHSA-vw86-c94w-v3x4 · Severity: high · Ecosystem: go — SiYuan: Publish Reader Path Traversal Delete via `removeUnusedAttributeView`

Affected software / configurations for CVE-2026-40318

Vendor Product Version Raw CPE
b3log siyuan < 3.6.4 cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*

References for CVE-2026-40318

cvelogic Threat Intelligence