{"items":[{"id":"NVI-00015411","kind":"vulnerability","title":"Netty: Fragmented ClientHello records trigger quadratic pre-handshake reassembly in default SNI parsing","revision":3,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected.","NVD lastModified does not establish freshness of every associated CPE record."],"lifecycle":"active","identifiers":["GHSA-fccg-mwvh-qqg4","CVE-2026-75596"],"plain_summary":"GitHub lists this reviewed advisory for io.netty:netty-handler, io.netty:netty-handler. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-10910f877736c91c8b5ba6033845499b"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-26T10:10:00.140Z","value":"7.5 HIGH (3.1)","meaning":"nvd@nist.gov severity; no combined Null risk score.","source_id":"sr-1ffe40656ea65066d485269f72debaab"},{"kind":"CVSS","as_of":"2026-10-26T10:10:00.140Z","value":"8.7 HIGH (4.0)","meaning":"security-advisories@github.com severity; no combined Null risk score.","source_id":"sr-1ffe40656ea65066d485269f72debaab"},{"kind":"EPSS","as_of":"2026-11-04T12:03:12.000Z","value":"0.374%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.31517. Missing scores are unknown.","source_id":"sr-10910f877736c91c8b5ba6033845499b"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-657a9b7b0905da1836a49cbe764f9370","url":"https://github.com/advisories/GHSA-fccg-mwvh-qqg4","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-fccg-mwvh-qqg4","publisher":"GitHub Advisory Database","observed_at":"2026-11-02T02:20:31.767Z"},{"id":"sr-1ffe40656ea65066d485269f72debaab","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-75596","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2026-75596","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-08T19:47:48.947Z"},{"id":"sr-10910f877736c91c8b5ba6033845499b","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-75596","publisher":"FIRST EPSS","observed_at":"2026-11-04T23:33:33.066Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-657a9b7b0905da1836a49cbe764f9370"],"technology":"io.netty:netty-handler","known_exclusions":[],"conditions_summary":"### Summary\n\nNetty's default SNI entrypoint reparses and recopies previously received ClientHello fragments on every additional TLS handshake record. A remote peer can send a small first record that advertises a large ClientHello length and then drip the body in many tiny records, causing **superlinear (quadratic) CPU work** before the handshake completes. With 4095 one-byte fragments, the handler recopies **8,386,560 bytes** from only **24,579 bytes** on the wire — a **341× amplification** ratio.\n\n### Affected Entrypoints\n\n- `io.netty.handler.ssl.SniHandler` — default constructors\n- `io.netty.handler.ssl.SslClientHelloHandler` — pre-handshake ClientHello aggregation path\n\n### Vulnerable Code Locations\n\n- `handler/src/main/java/io/netty/handler/ssl/SniHandler.java:85`\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:75` (decode entry)\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:165` (handshakeBuffer.clear)\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:174` (writeBytes re-copy)\n- `codec-base/src/main/java/io/netty/handler/codec/ByteToMessageDecoder.java:294` (cumulation retention)\n\n### Exploit Path\n\n```\n","public_affected_ranges":[">= 4.2.0.Final, <= 4.2.16.Final"]},{"certainty":"source_listed","source_ids":["sr-657a9b7b0905da1836a49cbe764f9370"],"technology":"io.netty:netty-handler","known_exclusions":[],"conditions_summary":"### Summary\n\nNetty's default SNI entrypoint reparses and recopies previously received ClientHello fragments on every additional TLS handshake record. A remote peer can send a small first record that advertises a large ClientHello length and then drip the body in many tiny records, causing **superlinear (quadratic) CPU work** before the handshake completes. With 4095 one-byte fragments, the handler recopies **8,386,560 bytes** from only **24,579 bytes** on the wire — a **341× amplification** ratio.\n\n### Affected Entrypoints\n\n- `io.netty.handler.ssl.SniHandler` — default constructors\n- `io.netty.handler.ssl.SslClientHelloHandler` — pre-handshake ClientHello aggregation path\n\n### Vulnerable Code Locations\n\n- `handler/src/main/java/io/netty/handler/ssl/SniHandler.java:85`\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:75` (decode entry)\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:165` (handshakeBuffer.clear)\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:174` (writeBytes re-copy)\n- `codec-base/src/main/java/io/netty/handler/codec/ByteToMessageDecoder.java:294` (cumulation retention)\n\n### Exploit Path\n\n```\n","public_affected_ranges":["<= 4.1.136.Final"]}],"null_published_at":"2026-11-08T19:53:44.037Z","source_updated_at":"2026-09-08T18:14:57.000Z","source_disclosed_at":"2026-09-08T18:14:56.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-11-02T02:20:31.767Z"},{"id":"NVI-00015411","kind":"vulnerability","title":"Netty: Fragmented ClientHello records trigger quadratic pre-handshake reassembly in default SNI parsing","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-fccg-mwvh-qqg4","CVE-2026-75596"],"plain_summary":"GitHub lists this reviewed advisory for io.netty:netty-handler, io.netty:netty-handler. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-10910f877736c91c8b5ba6033845499b"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"EPSS","as_of":"2026-11-04T12:03:12.000Z","value":"0.374%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.31517. Missing scores are unknown.","source_id":"sr-10910f877736c91c8b5ba6033845499b"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-657a9b7b0905da1836a49cbe764f9370","url":"https://github.com/advisories/GHSA-fccg-mwvh-qqg4","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-fccg-mwvh-qqg4","publisher":"GitHub Advisory Database","observed_at":"2026-11-02T02:20:31.767Z"},{"id":"sr-10910f877736c91c8b5ba6033845499b","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-75596","publisher":"FIRST EPSS","observed_at":"2026-11-04T23:33:33.066Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-657a9b7b0905da1836a49cbe764f9370"],"technology":"io.netty:netty-handler","known_exclusions":[],"conditions_summary":"### Summary\n\nNetty's default SNI entrypoint reparses and recopies previously received ClientHello fragments on every additional TLS handshake record. A remote peer can send a small first record that advertises a large ClientHello length and then drip the body in many tiny records, causing **superlinear (quadratic) CPU work** before the handshake completes. With 4095 one-byte fragments, the handler recopies **8,386,560 bytes** from only **24,579 bytes** on the wire — a **341× amplification** ratio.\n\n### Affected Entrypoints\n\n- `io.netty.handler.ssl.SniHandler` — default constructors\n- `io.netty.handler.ssl.SslClientHelloHandler` — pre-handshake ClientHello aggregation path\n\n### Vulnerable Code Locations\n\n- `handler/src/main/java/io/netty/handler/ssl/SniHandler.java:85`\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:75` (decode entry)\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:165` (handshakeBuffer.clear)\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:174` (writeBytes re-copy)\n- `codec-base/src/main/java/io/netty/handler/codec/ByteToMessageDecoder.java:294` (cumulation retention)\n\n### Exploit Path\n\n```\n","public_affected_ranges":[">= 4.2.0.Final, <= 4.2.16.Final"]},{"certainty":"source_listed","source_ids":["sr-657a9b7b0905da1836a49cbe764f9370"],"technology":"io.netty:netty-handler","known_exclusions":[],"conditions_summary":"### Summary\n\nNetty's default SNI entrypoint reparses and recopies previously received ClientHello fragments on every additional TLS handshake record. A remote peer can send a small first record that advertises a large ClientHello length and then drip the body in many tiny records, causing **superlinear (quadratic) CPU work** before the handshake completes. With 4095 one-byte fragments, the handler recopies **8,386,560 bytes** from only **24,579 bytes** on the wire — a **341× amplification** ratio.\n\n### Affected Entrypoints\n\n- `io.netty.handler.ssl.SniHandler` — default constructors\n- `io.netty.handler.ssl.SslClientHelloHandler` — pre-handshake ClientHello aggregation path\n\n### Vulnerable Code Locations\n\n- `handler/src/main/java/io/netty/handler/ssl/SniHandler.java:85`\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:75` (decode entry)\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:165` (handshakeBuffer.clear)\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:174` (writeBytes re-copy)\n- `codec-base/src/main/java/io/netty/handler/codec/ByteToMessageDecoder.java:294` (cumulation retention)\n\n### Exploit Path\n\n```\n","public_affected_ranges":["<= 4.1.136.Final"]}],"null_published_at":"2026-11-07T14:02:01.398Z","source_updated_at":"2026-09-08T18:14:57.000Z","source_disclosed_at":"2026-09-08T18:14:56.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.","null_first_observed_at":"2026-11-02T02:20:31.767Z"},{"id":"NVI-00015411","kind":"vulnerability","title":"Netty: Fragmented ClientHello records trigger quadratic pre-handshake reassembly in default SNI parsing","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-fccg-mwvh-qqg4","CVE-2026-75596"],"plain_summary":"GitHub lists this reviewed advisory for io.netty:netty-handler, io.netty:netty-handler. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-657a9b7b0905da1836a49cbe764f9370"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-657a9b7b0905da1836a49cbe764f9370","url":"https://github.com/advisories/GHSA-fccg-mwvh-qqg4","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-fccg-mwvh-qqg4","publisher":"GitHub Advisory Database","observed_at":"2026-11-02T02:20:31.767Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-657a9b7b0905da1836a49cbe764f9370"],"technology":"io.netty:netty-handler","known_exclusions":[],"conditions_summary":"### Summary\n\nNetty's default SNI entrypoint reparses and recopies previously received ClientHello fragments on every additional TLS handshake record. A remote peer can send a small first record that advertises a large ClientHello length and then drip the body in many tiny records, causing **superlinear (quadratic) CPU work** before the handshake completes. With 4095 one-byte fragments, the handler recopies **8,386,560 bytes** from only **24,579 bytes** on the wire — a **341× amplification** ratio.\n\n### Affected Entrypoints\n\n- `io.netty.handler.ssl.SniHandler` — default constructors\n- `io.netty.handler.ssl.SslClientHelloHandler` — pre-handshake ClientHello aggregation path\n\n### Vulnerable Code Locations\n\n- `handler/src/main/java/io/netty/handler/ssl/SniHandler.java:85`\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:75` (decode entry)\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:165` (handshakeBuffer.clear)\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:174` (writeBytes re-copy)\n- `codec-base/src/main/java/io/netty/handler/codec/ByteToMessageDecoder.java:294` (cumulation retention)\n\n### Exploit Path\n\n```\n","public_affected_ranges":[">= 4.2.0.Final, <= 4.2.16.Final"]},{"certainty":"source_listed","source_ids":["sr-657a9b7b0905da1836a49cbe764f9370"],"technology":"io.netty:netty-handler","known_exclusions":[],"conditions_summary":"### Summary\n\nNetty's default SNI entrypoint reparses and recopies previously received ClientHello fragments on every additional TLS handshake record. A remote peer can send a small first record that advertises a large ClientHello length and then drip the body in many tiny records, causing **superlinear (quadratic) CPU work** before the handshake completes. With 4095 one-byte fragments, the handler recopies **8,386,560 bytes** from only **24,579 bytes** on the wire — a **341× amplification** ratio.\n\n### Affected Entrypoints\n\n- `io.netty.handler.ssl.SniHandler` — default constructors\n- `io.netty.handler.ssl.SslClientHelloHandler` — pre-handshake ClientHello aggregation path\n\n### Vulnerable Code Locations\n\n- `handler/src/main/java/io/netty/handler/ssl/SniHandler.java:85`\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:75` (decode entry)\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:165` (handshakeBuffer.clear)\n- `handler/src/main/java/io/netty/handler/ssl/SslClientHelloHandler.java:174` (writeBytes re-copy)\n- `codec-base/src/main/java/io/netty/handler/codec/ByteToMessageDecoder.java:294` (cumulation retention)\n\n### Exploit Path\n\n```\n","public_affected_ranges":["<= 4.1.136.Final"]}],"null_published_at":"2026-11-03T10:03:31.363Z","source_updated_at":"2026-09-08T18:14:57.000Z","source_disclosed_at":"2026-09-08T18:14:56.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-02T02:20:31.767Z"}],"next_cursor":null,"snapshot_revision":"42594"}