External risk intelligence

SiYuan SQL Injection via FullTextSearchassetcontent Endpoint Affects Unauthenticated Users.

CVE advisorySeverity: CRITICAL (CVSS 9.9)

CVE-2026-69083

The vulnerability exists in a web application endpoint accessible to unauthenticated users. As SiYuan is commonly deployed as a network-accessible web service, the specific endpoint identified is reachable over the network without authentication, making it a likely target for internet-based exposure.

SQL Injection

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

SiYuan, a note-taking application, has a critical security vulnerability that could allow unauthorized users to execute malicious code. This SQL injection flaw impacts the full-text search function, potentially enabling attackers to access, alter, or delete sensitive data within the application's database. While the specific business impact depends on how SiYuan is deployed and used within your organization, its critical severity and network accessibility warrant attention.

Unauthenticated users can inject malicious code.
Sensitive data could be read, modified, or deleted.
Confirm relevance and assess potential exposure.

Attack Path

How an attacker could exploit the issue

An attacker can exploit this vulnerability by sending specially crafted requests to a web application's search endpoint. No authentication is needed to access this endpoint, which directly interacts with the application's database. By manipulating the search parameters, an attacker can inject malicious SQL code, potentially leading to unauthorized access and modification of sensitive data across the entire application.

No authentication required to access.
Malicious SQL injected via search parameters.
Risk of data theft or alteration.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow unauthenticated attackers to execute arbitrary SQL commands on the read-write asset-content database. This could affect data across notebooks by enabling unauthorized reading, modification, or deletion of content when the `fullTextSearchAssetContent` endpoint is exposed.

Cross-notebook data could be read or modified.
Via unescaped parameters and REGEXP clauses.
Unauthorized data access and modification.

Operational Fix

Recommended remediation, mitigation, and detection steps

SiYuan's fullTextSearchAssetContent endpoint is vulnerable to SQL injection, allowing unauthenticated attackers to execute arbitrary SQL commands. Owners of SiYuan deployments must first confirm the presence and reachability of this affected technology, then identify the accountable system owner. Remediation planning should prioritize business-critical and exposed instances.

Identify SiYuan deployment locations.
Verify exposure and criticality of instances.
Plan and coordinate remediation actions.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

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Frequently asked questions

What is SiYuan?

SiYuan is a local-first, privacy-focused note-taking application that supports features like block-style editing and knowledge graph visualization. It is often deployed as a web-accessible service, allowing users to host their own private cloud-like environment for managing notebooks and research documents. Because it stores data in a database, the application maintains active connections to handle content retrieval and search functionality.

What is the vulnerability in CVE-2026-69083?

This issue is an SQL injection, categorized as CWE-89. It happens when software fails to properly sanitize user-supplied input before using it in a database query. In this specific case, the `fullTextSearchAssetContent` endpoint does not escape parameters, allowing an attacker to insert their own SQL commands. These commands are then executed by the database, granting unauthorized control over data stored in the application.

How can an attacker trigger this vulnerability?

An attacker triggers this by sending a specially crafted network request to the `fullTextSearchAssetContent` endpoint. No login or authentication is required to reach this part of the software. It is important to note that sending standard, non-malicious search queries will not trigger the bug; the attack requires specific manipulation of parameters and the use of REGEXP clauses to bypass existing application logic and interface directly with the database.

Is my instance at risk?

If you host SiYuan, it is important to consider how it is deployed. Halo Surface Signal indicates this vulnerability is a likely target because the affected endpoint is accessible over the network without authentication. If your SiYuan instance is configured to be reachable from the internet, the risk is higher. Instances that are strictly isolated to a local network or VPN may have a reduced likelihood of immediate external targeting.

How do I respond to this threat?

First, identify all servers or containers running the SiYuan application within your environment. Verify whether the `fullTextSearchAssetContent` endpoint is reachable from outside your protected network. Once located, coordinate with the system owner to update your software to version 3.7.3 or later, which addresses the improper parameter handling. Prioritize updating instances that contain sensitive information or are accessible via the public internet.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.