CVE-2026-72799: SiYuan Information Disclosure Vulnerability

CVE-2026-72799 Overview

CVE-2026-72799 is an information disclosure vulnerability in SiYuan, an open-source personal knowledge management application. Versions at or below v3.7.2 fail to enforce publish-access filters on five filetree path-resolution endpoints. When an instance runs in publish mode with Publish.Auth.Enable set to false, unauthenticated readers can enumerate the complete private document tree. The exposed endpoints resolve notebook names, folder hierarchies, and document titles, including entries marked hidden, password-protected, or publish-forbidden. The issue is fixed in v3.7.4 and is classified as missing authorization [CWE-862].

Critical Impact
Anonymous network attackers can map the entire private document structure of a SiYuan instance running in publish mode without authentication.

Affected Products

SiYuan versions <= v3.7.2
SiYuan versions prior to v3.7.4
SiYuan instances operating in publish mode with Publish.Auth.Enable disabled

Discovery Timeline

2026-08-12 - CVE-2026-72799 published to NVD
2026-08-12 - Last updated in NVD database

Technical Details for CVE-2026-72799

Vulnerability Analysis

SiYuan exposes filetree APIs that translate between document identifiers, human-readable paths, and title paths. Five endpoints participate in this resolution: getFullHPathByID, getHPathByID, getPathByID, getIDsByHPath, and getHPathByPath. These endpoints do not consult the publish-access filter that governs which documents are visible in publish mode. As a result, any caller reaching the publish surface can request resolution for arbitrary identifiers or paths and receive canonical answers. Attackers use the responses to reconstruct notebook layouts, folder hierarchies, and document titles for content the operator never intended to expose. The disclosure covers documents flagged as hidden, protected by a document password, or explicitly marked publish-forbidden.

Root Cause

The root cause is missing authorization enforcement on server-side path-resolution handlers. The publish-mode access control layer filters rendering endpoints but is not applied to the metadata resolution endpoints. When Publish.Auth.Enable is false, the request context carries no authenticated principal, and the handlers proceed without verifying whether the target document is publishable.

Attack Vector

Exploitation requires only network reach to a SiYuan instance running in publish mode without publish authentication. An attacker sends HTTP requests to the five affected endpoints, iterating document IDs or path strings. Each response returns metadata mappings that let the attacker walk the full document tree. Publish reader tokens, when configured, also succeed because the endpoints ignore the publish filter entirely.

No verified exploit code is available. See the GitHub Security Advisory and the VulnCheck Advisory for additional detail.

Detection Methods for CVE-2026-72799

Indicators of Compromise

Access log entries showing repeated calls to getFullHPathByID, getHPathByID, getPathByID, getIDsByHPath, or getHPathByPath from a single client.
Requests to these endpoints originating from unauthenticated sessions when publish mode is enabled.
Sequential or enumerated document ID parameters in publish-mode API traffic.

Detection Strategies

Enable HTTP access logging on the SiYuan process and alert on high-volume calls to the five filetree resolution endpoints.
Correlate publish-mode API requests with the publish authentication setting to flag anonymous access to metadata endpoints.
Baseline normal publish traffic volume and alert on deviations that suggest enumeration.

Monitoring Recommendations

Forward SiYuan web server logs to a centralized logging platform for retention and query.
Monitor egress requests to internet-exposed SiYuan instances, especially those bound to public interfaces.
Track configuration state of Publish.Auth.Enable across managed SiYuan deployments.

How to Mitigate CVE-2026-72799

Immediate Actions Required

Upgrade SiYuan to v3.7.4 or later on all instances running publish mode.
Set Publish.Auth.Enable to true and require a publish password until the upgrade completes.
Restrict network access to publish-mode instances using firewall rules or reverse-proxy authentication.

Patch Information

The vendor addressed the issue in SiYuan v3.7.4. The fix enforces publish-access filters on the five affected filetree path-resolution endpoints so that hidden, password-protected, and publish-forbidden documents are not resolved for unauthorized callers. Release and patch detail are documented in the GitHub Security Advisory GHSA-5w7r-f4cg-rqq7.

Workarounds

Enable publish authentication by setting Publish.Auth.Enable to true and distributing credentials only to intended readers.
Place the publish endpoint behind a reverse proxy that enforces its own authentication layer.
Disable publish mode entirely if it is not required for the deployment.

bash

# Configuration example: enable publish authentication in SiYuan
# Set Publish.Auth.Enable = true and require a password
# Then restart SiYuan for the setting to take effect