{"items":[{"id":"NVI-00016159","kind":"vulnerability","title":"Netty: [codec-haproxy] Signed-Byte Sentinel Collision in HAProxyMessageDecoder Leads to Unbounded Memory Exhaustion","revision":2,"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-q6cq-mhr2-jmr5","CVE-2026-55851"],"plain_summary":"GitHub lists this reviewed advisory for io.netty:netty-codec-haproxy, io.netty:netty-codec-haproxy. 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-6e1dcafb14bd1315def1d6af9def20d7"],"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":"2026-07-30T14:48:31.250Z","value":"7.5 HIGH (3.1)","meaning":"nvd@nist.gov severity; no combined Null risk score.","source_id":"sr-6e1dcafb14bd1315def1d6af9def20d7"},{"kind":"CVSS","as_of":"2026-07-30T14:48:31.250Z","value":"8.7 HIGH (4.0)","meaning":"security-advisories@github.com severity; no combined Null risk score.","source_id":"sr-6e1dcafb14bd1315def1d6af9def20d7"}],"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-3423c5fcf5c03390e91b8733c057b082","url":"https://github.com/advisories/GHSA-q6cq-mhr2-jmr5","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-q6cq-mhr2-jmr5","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T22:34:39.734Z"},{"id":"sr-6e1dcafb14bd1315def1d6af9def20d7","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55851","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2026-55851","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-08T01:48:33.286Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-3423c5fcf5c03390e91b8733c057b082"],"technology":"io.netty:netty-codec-haproxy","known_exclusions":[],"conditions_summary":"The `HAProxyMessageDecoder` in netty's `codec-haproxy` module performs protocol version detection by reading the 13th byte of the inbound stream as a signed Java `byte` and widening it to `int` without masking. When an attacker sends a PROXY protocol v2 binary prefix (`0D 0A 0D 0A 00 0D 0A 51 55 49 54 0A`) followed by version byte `0xFF`, the sign extension produces `-1`, which collides with the decoder's \"need more data\" sentinel value. This collision traps the decoder in a version-detection loop where it perpetually requests more data without consuming any bytes, never instantiates the `HeaderExtractor` that enforces header size limits, and causes `ByteToMessageDecoder` to accumulate all subsequent inbound bytes into an unbounded `cumulation` buffer until the JVM exhausts its direct memory allocation.","public_affected_ranges":[">= 4.2.0.Final, <= 4.2.15.Final"]},{"certainty":"source_listed","source_ids":["sr-3423c5fcf5c03390e91b8733c057b082"],"technology":"io.netty:netty-codec-haproxy","known_exclusions":[],"conditions_summary":"The `HAProxyMessageDecoder` in netty's `codec-haproxy` module performs protocol version detection by reading the 13th byte of the inbound stream as a signed Java `byte` and widening it to `int` without masking. When an attacker sends a PROXY protocol v2 binary prefix (`0D 0A 0D 0A 00 0D 0A 51 55 49 54 0A`) followed by version byte `0xFF`, the sign extension produces `-1`, which collides with the decoder's \"need more data\" sentinel value. This collision traps the decoder in a version-detection loop where it perpetually requests more data without consuming any bytes, never instantiates the `HeaderExtractor` that enforces header size limits, and causes `ByteToMessageDecoder` to accumulate all subsequent inbound bytes into an unbounded `cumulation` buffer until the JVM exhausts its direct memory allocation.","public_affected_ranges":[">= 4.1.0.Final, <= 4.1.135.Final"]}],"null_published_at":"2026-11-08T19:53:48.746Z","source_updated_at":"2026-07-22T21:23:29.000Z","source_disclosed_at":"2026-07-22T21:23:25.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-11-03T22:34:39.734Z"},{"id":"NVI-00016159","kind":"vulnerability","title":"Netty: [codec-haproxy] Signed-Byte Sentinel Collision in HAProxyMessageDecoder Leads to Unbounded Memory Exhaustion","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-q6cq-mhr2-jmr5","CVE-2026-55851"],"plain_summary":"GitHub lists this reviewed advisory for io.netty:netty-codec-haproxy, io.netty:netty-codec-haproxy. 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-3423c5fcf5c03390e91b8733c057b082"],"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-3423c5fcf5c03390e91b8733c057b082","url":"https://github.com/advisories/GHSA-q6cq-mhr2-jmr5","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-q6cq-mhr2-jmr5","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T22:34:39.734Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-3423c5fcf5c03390e91b8733c057b082"],"technology":"io.netty:netty-codec-haproxy","known_exclusions":[],"conditions_summary":"The `HAProxyMessageDecoder` in netty's `codec-haproxy` module performs protocol version detection by reading the 13th byte of the inbound stream as a signed Java `byte` and widening it to `int` without masking. When an attacker sends a PROXY protocol v2 binary prefix (`0D 0A 0D 0A 00 0D 0A 51 55 49 54 0A`) followed by version byte `0xFF`, the sign extension produces `-1`, which collides with the decoder's \"need more data\" sentinel value. This collision traps the decoder in a version-detection loop where it perpetually requests more data without consuming any bytes, never instantiates the `HeaderExtractor` that enforces header size limits, and causes `ByteToMessageDecoder` to accumulate all subsequent inbound bytes into an unbounded `cumulation` buffer until the JVM exhausts its direct memory allocation.","public_affected_ranges":[">= 4.2.0.Final, <= 4.2.15.Final"]},{"certainty":"source_listed","source_ids":["sr-3423c5fcf5c03390e91b8733c057b082"],"technology":"io.netty:netty-codec-haproxy","known_exclusions":[],"conditions_summary":"The `HAProxyMessageDecoder` in netty's `codec-haproxy` module performs protocol version detection by reading the 13th byte of the inbound stream as a signed Java `byte` and widening it to `int` without masking. When an attacker sends a PROXY protocol v2 binary prefix (`0D 0A 0D 0A 00 0D 0A 51 55 49 54 0A`) followed by version byte `0xFF`, the sign extension produces `-1`, which collides with the decoder's \"need more data\" sentinel value. This collision traps the decoder in a version-detection loop where it perpetually requests more data without consuming any bytes, never instantiates the `HeaderExtractor` that enforces header size limits, and causes `ByteToMessageDecoder` to accumulate all subsequent inbound bytes into an unbounded `cumulation` buffer until the JVM exhausts its direct memory allocation.","public_affected_ranges":[">= 4.1.0.Final, <= 4.1.135.Final"]}],"null_published_at":"2026-11-04T10:04:27.900Z","source_updated_at":"2026-07-22T21:23:29.000Z","source_disclosed_at":"2026-07-22T21:23:25.000Z","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":"2026-11-03T22:34:39.734Z"}],"next_cursor":null,"snapshot_revision":"42594"}