VDB-398754 · CVE-2026-85580 · GCVE-0-2026-85580

SiYuan Note up to 3.8.1 MCP File-Access publishAccess.json information disclosure

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.3	$0-$5k	1.24

Summaryinfo

A vulnerability was found in SiYuan Note SiYuan up to 3.8.1. It has been declared as problematic. This issue affects some unknown processing of the file publishAccess.json of the component MCP File-Access Handler. The manipulation results in information disclosure. This vulnerability is cataloged as CVE-2026-85580. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as problematic has been found in SiYuan Note SiYuan up to 3.8.1. Affected is some unknown processing of the file publishAccess.json of the component MCP File-Access Handler. The manipulation with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. CVE summarizes:

SiYuan versions before v3.8.2 contain a path guard bypass vulnerability in the MCP file-access handler that uses case-sensitive matching on Linux filesystems. Attackers can read the protected publishAccess.json file by requesting case-variant paths like PublishAccess.json to disclose sensitive publish-access configuration and metadata.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-85580 since 09/04/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1592 by the MITRE ATT&CK project.

By approaching the search of inurl:publishAccess.json it is possible to find vulnerable targets with Google Hacking.

Upgrading to version 3.8.2 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

SiYuan Note

Name

SiYuan

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (VulnCheck): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Google Hack: 🔒
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: SiYuan 3.8.2

Timelineinfo

09/04/2026 Advisory disclosed
09/04/2026 +0 days CVE reserved
09/04/2026 +0 days VulDB entry created
09/04/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-85580 (🔒)
GCVE (CVE): GCVE-0-2026-85580
GCVE (VulDB): GCVE-100-398754

Entryinfo

Created: 09/04/2026 13:56
Changes: 09/04/2026 13:56 (77)
Complete: 🔍
Cache ID: 216::103