{"id":"CVE-2026-33871","aliases":["GHSA-w9fj-cfpg-grvv"],"url":"https://o3.security/vulnerability/CVE-2026-33871","summary":"Netty HTTP/2 CONTINUATION Frame Flood DoS via Zero-Byte Frame Bypass","details":"Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, a remote user can trigger a Denial of Service (DoS) against a Netty HTTP/2 server by sending a flood of `CONTINUATION` frames. The server's lack of a limit on the number of `CONTINUATION` frames, combined with a bypass of existing size-based mitigations using zero-byte frames, allows an user to cause excessive CPU consumption with minimal bandwidth, rendering the server unresponsive. Versions 4.1.132.Final and 4.2.10.Final fix the issue.","published":"2026-03-27T19:55:23.135Z","modified":"2026-08-07T11:31:11.643853930Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"io.netty:netty-codec-http2","fixedVersion":"4.1.132.Final"},{"ecosystem":"Maven","name":"io.netty:netty-codec-http2","fixedVersion":"4.2.11.Final"}],"fix":null,"references":[{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33871.json"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:10175"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:10184"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:13571"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:14272"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:14276"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:17668"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:17789"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:18054"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:18055"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:18059"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:22619"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:34608"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:7109"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:7380"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:8159"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:8509"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-33871"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33871.json"},{"type":"ADVISORY","url":"https://github.com/netty/netty/security/advisories/GHSA-w9fj-cfpg-grvv"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33871"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2452456"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:31:11.643853930Z"}}