CVE-2026-21874
Zauberzeug Nicegui 2.10.0 – 3.5.0
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LSummary
CVE-2026-21874 is a medium-severity Missing Release of Resource after Effective Lifetime (CWE-772) vulnerability in Zauberzeug Nicegui. Its CVSS base score is 5.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 41th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-1474
Vulnerability Data
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…
more
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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover missing resource releases through dynamic analysis or stress testing.
Requiring documented development standards and tools can mandate explicit resource-release patterns in code.
Resource-quota allocation limits the blast radius of an unreleased-resource exhaustion condition.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Lifecycle management explicitly requires handling resources through end-of-life including release.
Secure SDLC practices directly prevent missing resource-release defects during development.
Runtime monitoring may surface resource-exhaustion symptoms but does not address release logic.
Capacity monitoring can detect exhaustion caused by unreleased resources but does not prevent the root defect.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Explicit information-deletion requirements directly address timely release of resources after use.
Secure-SDLC practices include resource-management reviews, yet the control covers the entire lifecycle, not just this weakness.
Secure-coding rules can mandate explicit resource-release patterns, but the control is broader than this single weakness.
Change-management processes may catch missing de-allocation during reviews, but the control itself does not target resource lifetime.
Configuration baselines can enforce resource limits or timeouts, indirectly reducing exposure to leaks.