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medium·Product Based Web Vulnerabilities·Updated Apr 1, 2026

CVE-2026-34605 Scanner

CVE-2026-34605 Scanner - Cross-Site Scripting (XSS) vulnerability in SiYuan Note

Est. Time~10 seconds
Scan TypeSingle Scan
Targetsurl
CostFree
2.9k
Times Used
continuous scan runs
4.1k
Continuously Checked
assets under CS
0
Vulnerabilities Found
confirmed findings
References
CVECVE-2026-34605
8.6
CVSShigh
Exploitable remotely over the internet · no authentication required.

SiYuan is a personal knowledge management system. From version 3.6.0 to before version 3.6.2, the SanitizeSVG function introduced in version 3.6.0 to fix XSS in the unauthenticated /api/icon/getDynamicIcon endpoint can be bypassed by using namespace-prefixed element names such as <x:script xmlns:x="http://www.w3.org/2000/svg">. The Go HTML5 parser records the element's tag as "x:script" rather than "script", so the tag check passes it through. The SVG is served with Content-Type: image/svg+xml and no Content Security Policy; when a browser opens the response directly, its XML parser resolves the prefix to the SVG namespace and executes the embedded script. This issue has been patched in version 3.6.2.

Attack Vector
Network
Privileges Req.
None
User Interaction
A
Affected
siyuanby siyuan-note
>= 3.6.0, < 3.6.2
Updated Aug 19, 2026View on NVD →
Detail

SiYuan Note is a popular note-taking application used by individuals and professionals to organize information, support collaboration, and document key insights across various fields. It is designed to aid users in managing both personal and team notes, making it versatile for a wide array of projects and tasks. The application is valued for its intuitive interface and powerful organization tools, which streamline the process of note-taking and retrieval. Many educational institutions, project managers, and creative professionals rely on SiYuan Note for its robust feature set, enhancing productivity and efficiency. As a widely implemented solution, any discovered vulnerabilities can have significant implications for its diverse user base. The application's ongoing updates and improvements also aim to enhance user experience and security.

Cross-Site Scripting (XSS) is a vulnerability that allows attackers to inject malicious scripts into pages viewed by other users, potentially stealing session tokens or other sensitive information. This form of attack is particularly insidious as it runs code in the context of the victim's browser, exploiting any trust that may exist between the browser and the visited website. In SiYuan Note, the XSS vulnerability arises from inadequate filtering of SVG elements containing namespace prefixes that bypass security functions. This vulnerability can be leveraged by creating specifically crafted links that, when accessed by unsuspecting users, result in arbitrary JavaScript execution in the browser. Addressing such vulnerabilities is crucial to preventing unauthorized access and manipulation of the note-taking application's environment.

The vulnerability in SiYuan Note is exploited through the `/api/icon/getDynamicIcon` endpoint, which improperly processes SVG elements with a namespace prefix. Attackers can bypass the `SanitizeSVG` function by incorporating a namespaced script element, such as ``, allowing for execution of arbitrary JavaScript. This occurs when a user with the necessary privileges opens a crafted link leading to this endpoint, triggering the malfunction. The improper filtering does not strip the namespace, which ordinarily would prevent embedded scripts from executing. By targeting this path, attackers can achieve execution of scripts with full access to the victim's browser context, potentially gaining access to sensitive data or executing unauthorized actions.

Exploiting the XSS vulnerability could have severe consequences. Attackers executing XSS attacks might gain unauthorized access to user sessions, allowing them to perform actions on behalf of the victim. This unauthorized access can lead to data theft, unauthorized modifications, or the illicit use of features provided by SiYuan Note. If the victim is an authenticated user, attackers could extract sensitive information or manipulate existing data, compromising the integrity and confidentiality of all stored notes and related applications. This vulnerability, left unaddressed, poses a substantial risk to the security framework of the note-taking software, potentially facilitating broad spectrum breaches.

REFERENCES

Solution Advice
  • Upgrade to SiYuan Note version 3.6.2 or later to resolve the vulnerability.
  • Ensure SVG content is properly sanitized and stripped of all unnecessary namespace prefixes.
  • Implement strict Content Security Policy (CSP) to mitigate the risk of XSS attacks.
  • Perform regular security audits and penetration testing to identify and address potential vulnerabilities.
  • Educate users on safe browsing habits and the risks of visiting suspicious links.

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CVE-2026-34605 Scanner - Cross-Site Scripting (XSS) vulnerability in SiYuan Note | S4E