ZDF
Sign inSign up

Vulnerabilities

Security fix · CVE-2026-21874

NiceGUI is a Python-based UI framework.

Published Jan 8, 2026 · catalog updated Jan 8, 2026 · NiceGUI is a Python-based

Last checked Oct 31, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-21874. EPSS is 0.55%. Act only if a listed version of NiceGUI is a Python-based is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (NiceGUI is a Python-based).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium5.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.55%
Remediation
Version ranges on file
Affected products
vendor zauberzeug nicegui 2.10.0, < 3.5.0

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor zauberzeug nicegui 2.10.0, < 3.5.02.10.0, < 3.5.0

How to fix CVE-2026-21874

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-21874. EPSS is 0.55%. Act only if a listed version of NiceGUI is a Python-based is installed.

Which versions are affected?

Compare what you have installed with zauberzeug nicegui 2.10.0, < 3.5.0 2.10.0, < 3.5.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.55%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Jan 8, 2026 · EUVD

    Detected

    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

  2. Jan 8, 2026 · EUVD

    Updated

    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

Sources

  • CVE.orgVulnerability recordCVE-2026-21874

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-21874

    30-day exploitation probability 0.55%

    first.org
  • EUVDVulnerability recordEUVD-2026-1474

    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 servi

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Oct 31, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 31, 2026
  • CVE.orgOct 31, 2026
  • EUVDOct 30, 2026