CVE-2026-25516

NiceGUI is a Python-based UI framework. The ui.markdown() component uses the markdown2 library to convert markdown content to HTML, which is then rendered via innerHTML. By default, markdown2 allows raw HTML to pass through unchanged. This means that if an application renders user-controlled content through ui.markdown(), an attacker can inject malicious HTML containing JavaScript event handlers. Unlike other NiceGUI components that render HTML (ui.html(), ui.chat_message(), ui.interactive_image()), the ui.markdown() component does not provide or require a sanitize parameter, leaving applications vulnerable to XSS attacks. This vulnerability is fixed in 3.7.0.

CVSS v3 6.1 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/zauberzeug/nicegui/commit/f1f7533577875af7d23f161ed3627f73584cb561	Patch
https://github.com/zauberzeug/nicegui/security/advisories/GHSA-v82v-c5x8-w282	Exploit Mitigation Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:zauberzeug:nicegui:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-02-06 22:16

Updated : 2026-02-20 15:43

NVD link : CVE-2026-25516

Mitre link : CVE-2026-25516

CVE.ORG link : CVE-2026-25516

JSON object : View

Products Affected

zauberzeug

nicegui

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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