CVE-2026-21874 MEDIUM

CVE-2026-21874: NiceGUI has Redis connection leak via tab storage causes service degradation

Vendor Zauberzeug
Product nicegui
Weakness CWE-772
Published January 8, 2026
Last update January 8, 2026
View on NVD All CVEs

CVSS base score

5.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

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

What the vulnerability does

01Description

NiceGUI is a Python-based UI framework. From versions v2.10.0 to 3.4.1, an unauthenticated attacker can exhaust Redis connections by repeatedly opening and closing browser tabs on any NiceGUI application using Redis-backed storage. Connections are never released, leading to service degradation when Redis hits its connection limit. NiceGUI continues accepting new connections - errors are logged but the app stays up with broken storage functionality. This issue has been patched in version 3.5.0.

Key dates

02Disclosure timeline

January 8, 2026 CVE published
January 8, 2026 Record updated