{"schema":"threatline.record/2","record":{"id":"CVE-2026-100662","aliases":["GHSA-f64r-x647-cg8w"],"summary":"Netty HTTP/3 QPACK encoder-stream unbounded memory exhaustion DoS","details":"Netty's HTTP/3 codec (io.netty:netty-codec-http3) versions 4.2.0.Final through 4.2.17.Final contain an uncontrolled resource consumption vulnerability in the QPACK encoder-stream instruction decoder (QpackEncoderHandler, installed on the peer-initiated unidirectional QPACK encoder stream, type 0x02). The handler accepts an attacker-declared string-literal length of up to Integer.MAX_VALUE (~2 GiB) for the Name Length and Value Length fields of the \"Insert With Literal Name\" instruction (RFC 9204 §4.3.3), with no per-instruction or per-literal length cap and no cumulation-size limit; the existing HTTP/3 limits (maxHeaderListSize, maxUnknownFramePayloadLength, DEFAULT_MAX_FIELD_SECTION_SIZE) are not applied to this handler. A remote, unauthenticated peer with an established HTTP/3 connection to a default Netty HTTP/3 server can declare a very large literal length and then trickle fewer bytes than declared, causing the ByteToMessageDecoder MERGE cumulator to retain and grow the per-connection buffer, and ultimately triggering a large byte-array allocation. This leads to unbounded per-connection heap growth and OutOfMemoryError, resulting in denial of service. Fixed in 4.2.18.Final.","categories":["Frameworks"],"product":"netty","vendor":"netty","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-100662","source_modified_at":"2026-09-30T14:53:30.335Z","fetched_at":"2026-10-23T18:52:38.922436Z","product":"netty","vendor":"netty","versions":[{"lessThan":"4.2.18.Final","status":"affected","version":"4.2.0.Final","versionType":"custom"},{"status":"unaffected","version":"4.2.18.Final","versionType":"custom"}],"defaultStatus":"unaffected"},{"source":"GitHub Advisory Database","source_url":"https://github.com/netty/netty/security/advisories/GHSA-f64r-x647-cg8w","source_modified_at":"2026-09-28T23:13:48Z","fetched_at":"2026-10-24T00:31:04.721601Z","package":{"ecosystem":"maven","name":"io.netty:netty-codec-http3"},"range":">=4.2.0.Final, <= 4.2.17.Final"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-100662","source_modified_at":"2026-09-30T14:53:30.335Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"netty","ecosystem":null},"version":"4.2.18.Final","basis":"first unaffected version stated in the CVE record"},{"source":"GitHub Advisory Database","source_url":"https://github.com/netty/netty/security/advisories/GHSA-f64r-x647-cg8w","source_modified_at":"2026-09-28T23:13:48Z","fetched_at":"2026-10-24T00:31:04.721601Z","package":{"ecosystem":"maven","name":"io.netty:netty-codec-http3"},"version":"4.2.18.Final"}],"cvss":8.7,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00343,"percentile":0.26666,"score_date":"2026-10-23"},"published_at":"2026-09-26T13:23:28.990Z","modified_at":"2026-09-30T14:53:30.335Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-100662","fetched_at":"2026-10-23T18:52:38.922436Z","source_modified_at":"2026-09-30T14:53:30.335Z"},{"source":"GitHub Advisory Database","url":"https://github.com/netty/netty/security/advisories/GHSA-f64r-x647-cg8w","fetched_at":"2026-10-24T00:31:04.721601Z","source_modified_at":"2026-09-28T23:13:48Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-100662","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","GitHub Advisory Database","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/netty/netty/security/advisories/GHSA-f64r-x647-cg8w","tags":["exploit"]},{"source":"CVE List","url":"https://www.vulncheck.com/advisories/netty-http-3-qpack-encoder-stream-unbounded-memory-exhaustion-dos","tags":["third-party-advisory"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"poc","automatable":"yes","technical_impact":"partial","assessed_at":"2026-09-30T14:53:08.105333Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-09-30T14:53:30.335Z","content_hash":"4d96e0fcc77e787fb8b622540dd844249ac27eca278409a0c369d5d8292c741e"}}