{"answers":{"affected":"2 open source packages ship an affected version, including io.netty:netty-codec-http3. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-56816 in the wild and no public exploit code.","fix":"Upgrade io.netty:netty-codec-http3 to 4.2.16.Final or later.","what":"CVE-2026-56816 is a high-severity denial of service vulnerability in Netty Netty, published on 21 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-56816 and fix it if it is affected.\n\nWhat it is: CVE-2026-56816 is a high-severity denial of service vulnerability in Netty Netty, published on 21 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-56816 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- io.netty:netty-codec-http3 (Maven): affected all versions; fixed in 4.2.16.Final\n- io.netty:netty-codec-http3 (Maven): affected all versions; fixed in 4.2.16.Final\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-56816/ (Markdown: https://insights.sbomify.com/CVE-2026-56816/index.md)","id":"CVE-2026-56816","markdown":"https://insights.sbomify.com/CVE-2026-56816/index.md","name":"CVE-2026-56816","record":{"aliases":["CLEANSTART-2026-ET24110","CLEANSTART-2026-NR68186","DEBIAN-CVE-2026-56816","ECHO-d208-62e1-f7a7","GHSA-hpcc-26xq-25fv","MINI-2hvq-2mxv-6c6j","MINI-2m82-3mfx-wf49","MINI-39rc-8h5r-f5mv","MINI-8mpx-grmq-g36f","MINI-92ph-vpxh-64m9","MINI-h8r9-prr7-9vh8","MINI-jqwv-4f98-x499","MINI-q45w-v368-7mmq","MINI-vf8m-2858-rcj7","MINI-xvg7-38cq-q2rp","UBUNTU-CVE-2026-56816"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Java network framework","requires_auth":"none","summary":"An attacker can cause memory exhaustion and denial of service in Netty by sending HTTP/3 reserved frames with large payload lengths.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"netty","vendor":"netty"}],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-400","name":"Uncontrolled Resource Consumption"}],"description":"Netty is a network application framework for development of protocol servers and clients. Prior to 4.2.16.Final, Netty's `Http3FrameCodec` buffers incoming data for HTTP/3 reserved frame types up to the wire-specified payload length without limits; `decodeFrame` trusts `payLoadLength`, allowing an attacker to open multiple QUIC streams and send reserved frames with very large payload lengths to cause memory exhaustion and denial of service. This issue is fixed in version 4.2.16.Final.","ecosystems":["Maven"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Netty: Memory Exhaustion via HTTP/3 Reserved Frame Types","id":"CVE-2026-56816","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Maven","product":"netty:netty","products":["netty:netty"],"type":"denial_of_service","year":"2026"},"n_packages":2,"n_references":3,"next":{"headline":"Netty: XML External Entity (XXE) injection via unconfigured XML factory when DTD and entity processing are enabled","id":"CVE-2026-56817"},"packages":[{"ecosystem":"Maven","fixed":["4.2.16.Final"],"introduced":["0"],"last_affected":[],"package":"io.netty:netty-codec-http3","purl":null,"source":"GHSA-hpcc-26xq-25fv"},{"ecosystem":"Maven","fixed":["4.2.16.Final"],"introduced":["0"],"last_affected":[],"package":"io.netty:netty-codec-http3","purl":"pkg:maven/io.netty/netty-codec-http3","source":"GHSA-hpcc-26xq-25fv"}],"prev":{"headline":"Path traversal in pwnlift","id":"CVE-2026-56815"},"products":["netty"],"published":"2026-07-21","related":[{"cvss_score":9.1,"headline":"Netty: SNI Routing Bypass via Fragmented TLS ClientHello Causing Fallback to Default SslContext","id":"CVE-2026-75595","kev_date_added":null,"published":"2026-08-19"},{"cvss_score":8.7,"headline":"Netty: Fragmented ClientHello records trigger quadratic pre-handshake reassembly in default SNI parsing","id":"CVE-2026-75596","kev_date_added":null,"published":"2026-08-19"},{"cvss_score":8.7,"headline":"Netty Bzip2Decoder: Infinite Loop in RLE State Machine Leads to Event-Loop Thread Hang","id":"CVE-2026-59901","kev_date_added":null,"published":"2026-07-29"},{"cvss_score":8.7,"headline":"Netty codec-haproxy: Signed-Byte Sentinel Collision in HAProxyMessageDecoder Leads to Unbounded Memory Exhaustion","id":"CVE-2026-55851","kev_date_added":null,"published":"2026-07-21"},{"cvss_score":8.7,"headline":"Netty SpdyHttpDecoder: ByteBuf Reference Leak on RST_STREAM Leads to Native Memory Exhaustion","id":"CVE-2026-56745","kev_date_added":null,"published":"2026-07-21"},{"cvss_score":8.7,"headline":"Netty Vulnerable to DNS Cache Poisoning via Missing Bailiwick Checks in CNAME Records","id":"CVE-2026-45674","kev_date_added":null,"published":"2026-06-12"},{"cvss_score":8.7,"headline":"Netty has Insufficient Bailiwick Validation for NS Records","id":"CVE-2026-47691","kev_date_added":null,"published":"2026-06-12"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-07-22","vendors":["netty"]},"summary":"An attacker can cause memory exhaustion and denial of service in Netty by sending HTTP/3 reserved frames with large payload lengths.","url":"https://insights.sbomify.com/CVE-2026-56816/"}