{"id":"CVE-2026-21874","aliases":["GHSA-mp55-g7pj-rvm2","PYSEC-2026-1703"],"url":"https://o3.security/vulnerability/CVE-2026-21874","summary":"NiceGUI has Redis connection leak via tab storage causes service degradation","details":"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.","published":"2026-01-08T09:50:47.247Z","modified":"2026-08-07T11:50:14.524465799Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"nicegui","fixedVersion":"3.5.0"}],"fix":{"url":"https://github.com/zauberzeug/nicegui/commit/6c52eb2c90c4b67387c025b29646b4bc1578eb83","label":"zauberzeug/nicegui@6c52eb2"},"references":[{"type":"WEB","url":"https://github.com/zauberzeug/nicegui/releases/tag/v3.5.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21874.json"},{"type":"ADVISORY","url":"https://github.com/zauberzeug/nicegui/security/advisories/GHSA-mp55-g7pj-rvm2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-21874"},{"type":"FIX","url":"https://github.com/zauberzeug/nicegui/commit/6c52eb2c90c4b67387c025b29646b4bc1578eb83"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:50:14.524465799Z"}}