VDB-391058 · CVE-2026-73054 · EUVD-2026-59803

SiYuan Note up to 3.7.3 WebSocket Endpoint improper authentication

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.
6.3	$0-$5k	1.02

Summaryinfo

A vulnerability labeled as problematic has been found in SiYuan Note SiYuan up to 3.7.3. This affects an unknown function of the component WebSocket Endpoint. Such manipulation leads to improper authentication. This vulnerability is listed as CVE-2026-73054. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in SiYuan Note SiYuan up to 3.7.3. It has been rated as problematic. Affected by this issue is an unknown part of the component WebSocket Endpoint. The manipulation with an unknown input leads to a improper authentication vulnerability. Using CWE to declare the problem leads to CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. Impacted is confidentiality. CVE summarizes:

SiYuan versions before v3.7.4 contain an authentication bypass vulnerability in the WebSocket endpoint caused by differential parsing of query parameters between authentication exemption and session quarantine checks. Unauthenticated attackers can craft a malicious WebSocket URI with duplicated query parameters to bypass access auth code validation and receive the live kernel event stream including document identifiers, titles, and operation logs.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-73054 since 08/10/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available.

Upgrading to version 3.7.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-59803). 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: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
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: Improper authentication
CWE: CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
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 3.7.4

Timelineinfo

08/10/2026 CVE reserved
08/15/2026 +5 days Advisory disclosed
08/15/2026 +0 days VulDB entry created
08/16/2026 +1 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-73054 (🔒)
GCVE (CVE): GCVE-0-2026-73054
GCVE (VulDB): GCVE-100-391058
EUVD: 🔒

Entryinfo

Created: 08/15/2026 23:59
Updated: 08/16/2026 03:08
Changes: 08/15/2026 23:59 (76), 08/16/2026 03:08 (1)
Complete: 🔍
Cache ID: 216::103

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