TI-2026-17575 Aliases CVE-2026-21874 GHSA-mp55-g7pj-rvm2

NiceGUI has Redis connection leak via tab storage causes service degradation

MEDIUM 63CWE-772Published 2026-01-08 · Updated 2026-01-08

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · Low
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-772.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00554 46th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed nicegui (zauberzeug): 3.5.0nicegui (PyPI): 3.5.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
zauberzeug	nicegui	2.10.0 to before 3.5.0	3.5.0	Patch available	CNA
—	nicegui (PyPI)	2.10.0 to before 3.5.0	3.5.0	Patch available	GHSA-mp55-g7pj-rvm2

nicegui Vendorzauberzeug Affected 2.10.0 to before 3.5.0 Fixed in 3.5.0 Patch available CNA
nicegui (PyPI) Vendor— Affected 2.10.0 to before 3.5.0 Fixed in 3.5.0 Patch available GHSA-mp55-g7pj-rvm2

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:zauberzeug:nicegui::::::::	2.10.0 to before 3.5.0	Vulnerable	zauberzeug

cpe:2.3:a:zauberzeug:nicegui:*:*:*:*:*:*:*:* Versions 2.10.0 to before 3.5.0 Vulnerable ·zauberzeug

Remediation

Fix · CNA nicegui (zauberzeug) Fixed in 3.5.0
Fix · GHSA-mp55-g7pj-rvm2 nicegui (PyPI) Fixed in 3.5.0 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-21874
2026-10-03 Alias added: GHSA-mp55-g7pj-rvm2

References

Other 2

TI-2025-41029 NiceGUI Path Traversal Vulnerability in app.add_media_files() Allows Arbitrary File Reading CVSS 3.1HIGH 7.5
TI-2026-17574 Zero-click XSS in all NiceGUI apps which uses `ui.sub_pages` CVSS 3.1HIGH 7.2
TI-2026-17573 NiceGUI apps are vulnerable to XSS which uses `ui.sub_pages` and render arbitrary user-provided links CVSS 3.1MEDIUM 6.1
TI-2026-17572 NiceGUI is vulnerable to XSS via Unescaped URL in ui.navigate.history.push() / replace() CVSS 3.1MEDIUM 6.1
TI-2025-40897 NiceGUI Stored/Reflected XSS in ui.interactive_image via unsanitized SVG content CVSS 3.1MEDIUM 6.1
TI-2025-40896 NiceGUI Reflected XSS in ui.add_css, ui.add_scss, and ui.add_sass via Style Injection CVSS 3.1MEDIUM 6.1

See all 11 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences