{"schema":"threatline.record/2","record":{"id":"CVE-2026-100660","aliases":["GHSA-495p-pchh-r4mc"],"summary":"Netty before 4.2.18.Final QpackEncoder Unbounded Memory Retention","details":"Netty's HTTP/3 codec (io.netty:netty-codec-http3) from 4.2.0.Final through 4.2.17.Final retains unbounded per-stream QPACK encoder state. QpackEncoder stores a queue and a dynamic-table index tracker for every encoded field section that references the QPACK dynamic table, keyed by the peer-controlled QUIC stream ID, and these entries are released only when the remote decoder sends a Section Acknowledgment or Stream Cancellation instruction — not when the HTTP/3 stream completes. There is no limit on the number of tracked streams, field sections, or retained bytes. A remote, unauthenticated HTTP/3 client can advertise a non-zero QPACK dynamic-table capacity, acknowledge the table insertion so the server reuses a dynamically indexed response header, and then omit all mandatory Section Acknowledgments while issuing sequential requests over a single QUIC connection, bypassing concurrent-stream limits and causing unbounded heap growth until the server exhausts memory (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-2026-100660","source_modified_at":"2026-09-28T16:45:45.821Z","fetched_at":"2026-10-23T18:52:38.922436Z","product":"netty","vendor":"netty","versions":[{"version":"0","status":"affected","versionType":"custom","lessThan":"4.2.18.Final"},{"version":"4.2.18.Final","status":"unaffected","versionType":"custom"}],"defaultStatus":"unaffected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-100660","source_modified_at":"2026-09-28T16:45:45.821Z","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"}],"cvss":8.7,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00375,"percentile":0.30308,"score_date":"2026-10-23"},"published_at":"2026-09-26T13:23:27.554Z","modified_at":"2026-09-28T16:45:45.821Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-100660","fetched_at":"2026-10-23T18:52:38.922436Z","source_modified_at":"2026-09-28T16:45:45.821Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-100660","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/netty/netty/security/advisories/GHSA-495p-pchh-r4mc","tags":["exploit"]},{"source":"CVE List","url":"https://www.vulncheck.com/advisories/netty-before-4.2.18-final-qpackencoder-unbounded-memory-retention","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":"2026-09-28T16:45:17.094549Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-09-28T16:45:45.821Z","content_hash":"c31c225c9891182eb7ca61ee783e96764f5dd6d636eb73965f8432b6aa858530"}}