SiYuan-Note SiYuan up to 3.7.3 Backlink Endpoint /api/ref/refreshBacklink improper authorization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.3$0-$5k1.89

Summaryinfo

A vulnerability was found in SiYuan-Note SiYuan up to 3.7.3. It has been declared as critical. The impacted element is an unknown function of the file /api/ref/refreshBacklink of the component Backlink Endpoint. Such manipulation leads to improper authorization. This vulnerability is referenced as CVE-2026-72812. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in SiYuan-Note SiYuan up to 3.7.3. Affected by this issue is some unknown processing of the file /api/ref/refreshBacklink of the component Backlink Endpoint. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is integrity, and availability. CVE summarizes:

SiYuan versions before v3.7.4 contain a missing authorization vulnerability in the /api/ref/refreshBacklink endpoint that allows anonymous readers to trigger persistent server-side writes. Attackers can invoke the endpoint with an attacker-controlled block ID to flush transaction queues, scan all references globally, and enqueue database writes, bypassing read-only protections and enabling resource amplification attacks.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-72812 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. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1548.002 by the MITRE ATT&CK project.

Upgrading to version 3.7.4 eliminates this vulnerability.

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Productinfo

Vendor

Name

Version

Website

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: 6.5
VulDB Meta Temp Score: 6.3

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

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

CVSSv2info

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

Exploitinginfo

Class: Improper authorization
CWE: CWE-285 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

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

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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
08/14/2026 +4 days Advisory disclosed
08/14/2026 +0 days VulDB entry created
08/14/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-72812 (🔒)
GCVE (CVE): GCVE-0-2026-72812
GCVE (VulDB): GCVE-100-389990

Entryinfo

Created: 08/14/2026 13:57
Changes: 08/14/2026 13:57 (77)
Complete: 🔍
Cache ID: 216::103

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