{"id":"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.","aliases":["GHSA-w9fj-cfpg-grvv"],"modified":"2026-04-02T13:29:16.632756Z","published":"2026-03-27T19:55:23.135Z","related":["CGA-pfvr-2rwf-cg7p","openSUSE-SU-2026:10463-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33871.json","cwe_ids":["CWE-770"],"cna_assigner":"GitHub_M"},"references":[{"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/netty/netty","events":[{"introduced":"0"},{"fixed":"ec119d487b3a27e4ac118e7e1d97f0c96a85f4a3"}],"database_specific":{"versions":[{"introduced":"0"},{"fixed":"4.1.132.Final"}]}},{"type":"GIT","repo":"https://github.com/netty/netty","events":[{"introduced":"5451fbb0effd8460f57013bb33aefeb953144ed9"},{"fixed":"4cc98736c3947bc93122e0b64e0bd8fc970c6437"}],"database_specific":{"versions":[{"introduced":"4.2.0.Alpha1"},{"fixed":"4.2.10.Final"}]}}],"versions":["netty-3.10.0.Final","netty-3.10.1.Final","netty-3.10.2.Final","netty-3.10.3.Final","netty-3.10.4.Final","netty-3.10.5.Final","netty-3.10.6.Final","netty-3.2.10.Final","netty-3.2.4.Final","netty-3.2.5.Final","netty-3.2.6.Final","netty-3.2.7.Final","netty-3.2.8.Final","netty-3.2.9.Final","netty-3.3.0.Final","netty-3.3.1.Final","netty-3.4.0.Alpha1","netty-3.4.0.Alpha2","netty-3.4.0.Beta1","netty-3.4.0.Final","netty-3.4.1.Final","netty-3.4.2.Final","netty-3.4.3.Final","netty-3.4.4.Final","netty-3.4.5.Final","netty-3.4.6.Final","netty-3.5.0.Beta1","netty-3.5.0.Final","netty-3.5.1.Final","netty-3.5.10.Final","netty-3.5.11.Final","netty-3.5.12.Final","netty-3.5.13.Final","netty-3.5.2.Final","netty-3.5.3.Final","netty-3.5.4.Final","netty-3.5.5.Final","netty-3.5.6.Final","netty-3.5.7.Final","netty-3.5.8.Final","netty-3.5.9.Final","netty-3.6.0.Beta1","netty-3.6.0.Final","netty-3.6.1.Final","netty-3.6.10.Final","netty-3.6.2.Final","netty-3.6.3.Final","netty-3.6.4.Final","netty-3.6.5.Final","netty-3.6.6.Final","netty-3.6.7.Final","netty-3.6.8.Final","netty-3.6.9.Final","netty-3.7.0.Final","netty-3.7.1.Final","netty-3.8.0.Final","netty-3.8.1.Final","netty-3.8.2.Final","netty-3.8.3.Final","netty-3.9.0.Final","netty-3.9.1.1.Final","netty-3.9.1.Final","netty-3.9.2.Final","netty-3.9.3.Final","netty-3.9.4.Final","netty-3.9.5.Final","netty-3.9.6.Final","netty-3.9.7.Final","netty-3.9.8.Final","netty-3.9.9.Final","netty-4.0.0.Alpha1","netty-4.0.0.Alpha2","netty-4.0.0.Alpha3","netty-4.0.0.Alpha4","netty-4.0.0.Alpha5","netty-4.0.0.Alpha6","netty-4.0.0.Alpha7","netty-4.0.0.Alpha8","netty-4.0.0.Beta1","netty-4.0.0.Beta2","netty-4.0.0.Beta3","netty-4.0.0.CR1","netty-4.0.0.CR2","netty-4.0.0.CR3","netty-4.0.0.CR4","netty-4.0.0.CR5","netty-4.0.0.CR6","netty-4.0.0.CR7","netty-4.0.0.CR8","netty-4.0.0.CR9","netty-4.0.0.Final","netty-4.0.1.Final","netty-4.0.10.Final","netty-4.0.11.Final","netty-4.0.12.Final","netty-4.0.13.Final","netty-4.0.14.Beta1","netty-4.0.14.Final","netty-4.0.15.Final","netty-4.0.16.Final","netty-4.0.17.Final","netty-4.0.18.Final","netty-4.0.19.Final","netty-4.0.2.Final","netty-4.0.20.Final","netty-4.0.21.Final","netty-4.0.22.Final","netty-4.0.23.Final","netty-4.0.24.Final","netty-4.0.25.Final","netty-4.0.26.Final","netty-4.0.27.Final","netty-4.0.28.Final","netty-4.0.29.Final","netty-4.0.3.Final","netty-4.0.30.Final","netty-4.0.31.Final","netty-4.0.32.Final","netty-4.0.33.Final","netty-4.0.34.Final","netty-4.0.35.Final","netty-4.0.36.Final","netty-4.0.37.Final","netty-4.0.38.Final","netty-4.0.39.Final","netty-4.0.4.Final","netty-4.0.40.Final","netty-4.0.41.Final","netty-4.0.42.Final","netty-4.0.43.Final","netty-4.0.44.Final","netty-4.0.45.Final","netty-4.0.46.Final","netty-4.0.47.Final","netty-4.0.48.Final","netty-4.0.49.Final","netty-4.0.5.Final","netty-4.0.50.Final","netty-4.0.51.Final","netty-4.0.52.Final","netty-4.0.53.Final","netty-4.0.54.Final","netty-4.0.55.Final","netty-4.0.56.Final","netty-4.0.6.Final","netty-4.0.7.Final","netty-4.0.8.Final","netty-4.0.9.Final","netty-4.1.0.Beta1","netty-4.1.0.Beta2","netty-4.1.0.Beta3","netty-4.1.0.Beta4","netty-4.1.0.Beta5","netty-4.1.0.Beta6","netty-4.1.0.Beta7","netty-4.1.0.Beta8","netty-4.1.0.CR1","netty-4.1.0.CR2","netty-4.1.0.CR3","netty-4.1.0.CR4","netty-4.1.0.CR5","netty-4.1.0.CR6","netty-4.1.0.CR7","netty-4.1.0.Final","netty-4.1.1.Final","netty-4.1.10.Final","netty-4.1.100.Final","netty-4.1.101.Final","netty-4.1.102.Final","netty-4.1.103.Final","netty-4.1.104.Final","netty-4.1.105.Final","netty-4.1.106.Final","netty-4.1.107.Final","netty-4.1.108.Final","netty-4.1.109.Final","netty-4.1.11.Final","netty-4.1.110.Final","netty-4.1.111.Final","netty-4.1.112.Final","netty-4.1.113.Final","netty-4.1.114.Final","netty-4.1.115.Final","netty-4.1.116.Final","netty-4.1.117.Final","netty-4.1.118.Final","netty-4.1.11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