{"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":"2026-04-16T08:44:12.986203372Z","published":"2026-03-27T19:55:23.135Z","related":["CGA-pfvr-2rwf-cg7p","SUSE-SU-2026:1353-1","openSUSE-SU-2026:10463-1"],"database_specific":{"cwe_ids":["CWE-770"],"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33871.json"},"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"},{"introduced":"5451fbb0effd8460f57013bb33aefeb953144ed9"},{"fixed":"4cc98736c3947bc93122e0b64e0bd8fc970c6437"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"4.1.132.Final"},{"introduced":"4.2.0.Alpha1"},{"fixed":"4.2.10.Final"}],"source":"AFFECTED_FIELD"}}],"versions":["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.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-4.0.2.Final","netty-4.0.3.Final","netty-4.0.4.Final","netty-4.0.5.Final","netty-4.0.6.Final","netty-4.0.7.Final","netty-4.0.8.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-4.1.119.Final","netty-4.1.12.Final","netty-4.1.120.Final","netty-4.1.121.Final","netty-4.1.122.Final","netty-4.1.123.Final","netty-4.1.124.Final","netty-4.1.125.Final","netty-4.1.126.Final","netty-4.1.127.Final","netty-4.1.128.Final","netty-4.1.129.Final","netty-4.1.13.Final","netty-4.1.130.Final","netty-4.1.131.Final","netty-4.1.14.Final","netty-4.1.15.Final","netty-4.1.16.Final","netty-4.1.17.Final","netty-4.1.18.Final","netty-4.1.19.Final","netty-4.1.2.Final","netty-4.1.20.Final","netty-4.1.21.Final","netty-4.1.22.Final","netty-4.1.23.Final","netty-4.1.24.Final","netty-4.1.25.Final","netty-4.1.26.Final","netty-4.1.27.Final","netty-4.1.28.Final","netty-4.1.29.Final","netty-4.1.3.Final","netty-4.1.30.Final","netty-4.1.31.Final","netty-4.1.32.Final","netty-4.1.33.Final","netty-4.1.34.Final","netty-4.1.35.Final","netty-4.1.36.Final","netty-4.1.37.Final","netty-4.1.38.Final","netty-4.1.39.Final","netty-4.1.4.Final","netty-4.1.40.Final","netty-4.1.41.Final","netty-4.1.42.Final","netty-4.1.43.Final","netty-4.1.44.Final","netty-4.1.45.Final","netty-4.1.46.Final","netty-4.1.47.Final","netty-4.1.48.Final","netty-4.1.49.Final","netty-4.1.5.Final","netty-4.1.50.Final","netty-4.1.51.Final","netty-4.1.52.Final","netty-4.1.53.Final","netty-4.1.54.Final","netty-4.1.55.Final","netty-4.1.56.Final","netty-4.1.57.Final","netty-4.1.58.Final","netty-4.1.59.Final","netty-4.1.6.Final","netty-4.1.60.Final","netty-4.1.61.Final","netty-4.1.62.Final","netty-4.1.63.Final","netty-4.1.64.Final","netty-4.1.65.Final","netty-4.1.66.Final","netty-4.1.67.Final","netty-4.1.68.Final","netty-4.1.69.Final","netty-4.1.7.Final","netty-4.1.70.Final","netty-4.1.71.Final","netty-4.1.72.Final","netty-4.1.73.Final","netty-4.1.74.Final","netty-4.1.75.Final","netty-4.1.76.Final","netty-4.1.77.Final","netty-4.1.78.Final","netty-4.1.79.Final","netty-4.1.8.Final","netty-4.1.80.Final","netty-4.1.81.Final","netty-4.1.82.Final","netty-4.1.83.Final","netty-4.1.84.Final","netty-4.1.85.Final","netty-4.1.86.Final","netty-4.1.87.Final","netty-4.1.88.Final","netty-4.1.89.Final","netty-4.1.9.Final","netty-4.1.90.Final","netty-4.1.91.Final","netty-4.1.92.Final","netty-4.1.93.Final","netty-4.1.94.Final","netty-4.1.95.Final","netty-4.1.96.Final","netty-4.1.97.Final","netty-4.1.98.Final","netty-4.1.99.Final","netty-4.2.0.Alpha1","netty-4.2.0.Alpha2","netty-4.2.0.Alpha3","netty-4.2.0.A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