Which versions of SiYuan are affected by EUVD-2026-52276?

SiYuan knowledge management platform versions prior to 3.7.3 contain a critical SQL injection vulnerability that allows unauthenticated attackers to read, modify, or delete all stored notebooks…. A patch is available.

Is there a public PoC exploit available for EUVD-2026-52276?

Yes, a public proof-of-concept exploit is available for EUVD-2026-52276. Prioritise patching immediately. EPSS: 0.4%.

How to fix or mitigate EUVD-2026-52276?

Within 24 hours, immediately update all SiYuan instances to version 3.7.3 or later to apply the vendor-released patch. Within 7 days, verify complete deployment across all production and non-production SiYuan installations and confirm no legacy versions remain in service. Within 30 days, review database access logs and notebook modification histories for the pre-patch period to identify any unauthorized access or data tampering and implement log retention policies for future incident investigation.

SiYuan EUVD-2026-52276

Q: What is the CVSS score of EUVD-2026-52276?

EUVD-2026-52276 has a CVSS 4.0 base score of 9.9 (Critical). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.4%.

| CVE-2026-69083 CRITICAL

SQL Injection (CWE-89)

2026-08-03 VulnCheck

GHSA-fph3-ghq9-vw66

GHSA-pqpf-6vqv-6w92

SQLi Siyuan Siyuan Note

9.9

CVSS 4.0 · Vendor: VulnCheck

Severity by source

Vendor (VulnCheck) PRIMARY

9.9 CRITICAL

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

10.0 CRITICAL

Endpoint is remotely reachable without authentication (AV:N/AC:L/PR:N/UI:N); injection into a read-write DASsET DB yields high confidentiality and integrity impact across notebooks (scope change, S:C), with no described availability effect.

3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Aug 03, 2026 - 14:27 vuln.today

Patch available

Aug 03, 2026 - 14:02 EUVD

CVE Published

Aug 03, 2026 - 13:20 cve.org

CRITICAL 9.9

DescriptionCVE.org

SiYuan versions before v3.7.3 contain SQL injection vulnerabilities in the fullTextSearchAssetContent endpoint reachable by unauthenticated users and publish RoleReader tokens. Attackers can execute arbitrary SQL on the read-write asset-content database via unescaped method parameters and REGEXP clauses to read, modify, or delete cross-notebook data.

AnalysisAI

SQL injection in SiYuan's fullTextSearchAssetContent endpoint lets unauthenticated attackers and holders of publish RoleReader tokens execute arbitrary SQL against the read-write asset-content database in all versions before v3.7.3. Because the endpoint is reachable without authentication and the database is writable, attackers can read, alter, or delete data across notebooks - not merely exfiltrate it. No public exploit identified at time of analysis, but the flaw was reported by VulnCheck and carries a CVSS 4.0 base score of 9.9.

Technical ContextAI

SiYuan is a self-hosted, block-based personal knowledge management and note-taking application (vendor siyuan-note) that stores note and asset content in a local SQLite-style database and exposes HTTP API endpoints, including a publishing mode with role-scoped tokens (e.g. RoleReader). The vulnerability is a classic CWE-89 SQL Injection: the fullTextSearchAssetContent handler builds queries using unescaped 'method' parameters and REGEXP clauses, allowing user-controlled input to break out of the intended query context. Critically, the injection targets the asset-content database in read-write mode, so the impact extends beyond data disclosure to arbitrary modification and deletion. The affected component is identified by CPE cpe:2.3:a:siyuan-note:siyuan:*:*:*:*:*:*:*:* across all releases prior to 3.7.3.

RemediationAI

Upgrade SiYuan to v3.7.3 or later, which the vendor advisory (GHSA-fph3-ghq9-vw66) confirms contains the fix - patch available per vendor advisory. Until upgrading, reduce exposure by restricting network reachability of the SiYuan HTTP API: do not expose the instance or its publish endpoints directly to the internet, place it behind an authenticating reverse proxy or VPN, and disable or lock down publishing mode / RoleReader token issuance if not required, since these tokens are among the affected access paths (trade-off: publishing and shared-read features become unavailable). If the fullTextSearchAssetContent endpoint can be blocked at the proxy without breaking search for legitimate users, do so as a temporary control. Consult https://www.vulncheck.com/advisories/siyuan-before-sql-injection-via-fulltextsearchassetcontent for further detail. These are compensating controls only; the definitive fix is the v3.7.3 upgrade.