SiYuan Note up to 3.7.3 Autocomplete Hint Popup extend.ts genHintItemHTML cross site scripting

Summaryinfo

A vulnerability identified as problematic has been detected in SiYuan Note SiYuan up to 3.7.3. Affected is the function genHintItemHTML of the file app/src/protyle/hint/extend.ts of the component Autocomplete Hint Popup. This manipulation causes cross site scripting. This vulnerability appears as CVE-2026-75916. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in SiYuan Note SiYuan up to 3.7.3. It has been declared as problematic. Affected by this vulnerability is the function genHintItemHTML of the file app/src/protyle/hint/extend.ts of the component Autocomplete Hint Popup. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. The summary by CVE is:

SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the '((' block-reference autocomplete hint popup. In genHintItemHTML() (app/src/protyle/hint/extend.ts), a candidate block's name, alias, and memo fields are concatenated into the popup's HTML without escaping. An attacker who can set these metadata fields on a block can inject a self-firing payload (e.g. <img src=x onerror=...>) that executes automatically when a victim types '((' followed by a search term that surfaces the crafted block. Because SiYuan's Electron windows run with nodeIntegration enabled, contextIsolation disabled, and no CSP, the injected script gains require('child_process') access, allowing the XSS to escalate to arbitrary OS command execution.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-75916 since 08/18/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• SiYuan Note

Name

• SiYuan

Version

• 3.7.0
• 3.7.1
• 3.7.2
• 3.7.3

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion