CVE-2026-21874
Medium · 5.3NiceGUI has Redis connection leak via tab storage causes service degradation
CVSS
5.3
EPSS
0.6%
Published
Jan 8, 2026
CISA due date
—
The record
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.**
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| PyPI | nicegui | 2.10.0 | 3.5.0 |
| pypi | nicegui | 2.10.0 | No fix |
Related vulnerabilities
- GHSA-mp55-g7pj-rvm2 NiceGUI has Redis connection leak via tab storage causes service degradation Same vulnerability
- GHSA-78qv-3mpx-9cqq NiceGUI vulnerable to XSS via Code Injection during client-side element function execution Also affects nicegui
- CVE-2026-27156 NiceGUI is a Python-based UI framework. Also affects nicegui
- CVE-2026-25732 NiceGUI is a Python-based UI framework. Also affects nicegui
- CVE-2026-25516 NiceGUI is a Python-based UI framework. Also affects nicegui
- GHSA-9ffm-fxg3-xrhh NiceGUI's Path Traversal via Unsanitized FileUpload.name Enables Arbitrary File Write Also affects nicegui
- GHSA-v82v-c5x8-w282 NiceGUI's XSS vulnerability in ui.markdown() allows arbitrary JavaScript execution… Also affects nicegui
- GHSA-mhpg-c27v-6mxr NiceGUI apps which use `ui.sub_pages` vulnerable to zero-click XSS Also affects nicegui