{"items":[{"id":"NVI-00009034","kind":"vulnerability","title":"h11 accepts some malformed Chunked-Encoding bodies","revision":3,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-vqfr-h8mv-ghfj","CVE-2025-43859"],"plain_summary":"GitHub lists this reviewed advisory for h11. 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-0ecdc6cd5fa46cb81bac3173d84f8419"],"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":"2026-10-27T16:31:16.000Z","value":"9.1 critical","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-832e3e9a017377158d7b5e07ea29ce68"},{"kind":"EPSS","as_of":"2026-11-03T12:00:27.000Z","value":"0.594%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.48453. Missing scores are unknown.","source_id":"sr-0ecdc6cd5fa46cb81bac3173d84f8419"}],"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-832e3e9a017377158d7b5e07ea29ce68","url":"https://github.com/advisories/GHSA-vqfr-h8mv-ghfj","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-vqfr-h8mv-ghfj","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T21:56:51.534Z"},{"id":"sr-0ecdc6cd5fa46cb81bac3173d84f8419","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-2025-43859","publisher":"FIRST EPSS","observed_at":"2026-11-03T17:44:07.767Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-832e3e9a017377158d7b5e07ea29ce68"],"technology":"h11","known_exclusions":[],"conditions_summary":"### Impact\n\nA leniency in h11's parsing of line terminators in chunked-coding message bodies can lead to request smuggling vulnerabilities under certain conditions.\n\n### Details\n\nHTTP/1.1 Chunked-Encoding bodies are formatted as a sequence of \"chunks\", each of which consists of:\n\n- chunk length\n- `\\r\\n`\n- `length` bytes of content\n- `\\r\\n`\n\nIn versions of h11 up to 0.14.0, h11 instead parsed them as:\n\n- chunk length\n- `\\r\\n`\n- `length` bytes of content\n- any two bytes\n\ni.e. it did not validate that the trailing `\\r\\n` bytes were correct, and if you put 2 bytes of garbage there it would be accepted, instead of correctly rejecting the body as malformed.\n\nBy itself this is harmless. However, suppose you have a proxy or reverse-proxy that tries to analyze HTTP requests, and your proxy has a _different_ bug in parsing Chunked-Encoding, acting as if the format is:\n\n- chunk length\n- `\\r\\n`\n- `length` bytes of content\n- more bytes of content, as many as it takes until you find a `\\r\\n`\n\nFor example, pound had this bug -- it can happen if an implementer uses a generic \"read until end of line\" helper to consumes the trailing `\\r\\n`.\n\nIn this cas","public_affected_ranges":["< 0.16.0"]}],"null_published_at":"2026-11-06T00:29:57.259Z","source_updated_at":"2026-10-27T16:31:16.000Z","source_disclosed_at":"2025-04-24T16:07:56.000Z","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":"2026-10-31T21:56:51.534Z"},{"id":"NVI-00009034","kind":"vulnerability","title":"h11 accepts some malformed Chunked-Encoding bodies","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-vqfr-h8mv-ghfj","CVE-2025-43859"],"plain_summary":"GitHub lists this reviewed advisory for h11. 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-1b08a6b2a27f2c678aa3f084e890b3fb"],"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":"2026-10-27T16:31:16.000Z","value":"9.1 critical","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-832e3e9a017377158d7b5e07ea29ce68"},{"kind":"EPSS","as_of":"2026-10-31T12:00:27.000Z","value":"0.594%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.48419. Missing scores are unknown.","source_id":"sr-1b08a6b2a27f2c678aa3f084e890b3fb"}],"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-832e3e9a017377158d7b5e07ea29ce68","url":"https://github.com/advisories/GHSA-vqfr-h8mv-ghfj","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-vqfr-h8mv-ghfj","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T21:56:51.534Z"},{"id":"sr-1b08a6b2a27f2c678aa3f084e890b3fb","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-2025-43859","publisher":"FIRST EPSS","observed_at":"2026-10-31T22:06:15.371Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-832e3e9a017377158d7b5e07ea29ce68"],"technology":"h11","known_exclusions":[],"conditions_summary":"### Impact\n\nA leniency in h11's parsing of line terminators in chunked-coding message bodies can lead to request smuggling vulnerabilities under certain conditions.\n\n### Details\n\nHTTP/1.1 Chunked-Encoding bodies are formatted as a sequence of \"chunks\", each of which consists of:\n\n- chunk length\n- `\\r\\n`\n- `length` bytes of content\n- `\\r\\n`\n\nIn versions of h11 up to 0.14.0, h11 instead parsed them as:\n\n- chunk length\n- `\\r\\n`\n- `length` bytes of content\n- any two bytes\n\ni.e. it did not validate that the trailing `\\r\\n` bytes were correct, and if you put 2 bytes of garbage there it would be accepted, instead of correctly rejecting the body as malformed.\n\nBy itself this is harmless. However, suppose you have a proxy or reverse-proxy that tries to analyze HTTP requests, and your proxy has a _different_ bug in parsing Chunked-Encoding, acting as if the format is:\n\n- chunk length\n- `\\r\\n`\n- `length` bytes of content\n- more bytes of content, as many as it takes until you find a `\\r\\n`\n\nFor example, pound had this bug -- it can happen if an implementer uses a generic \"read until end of line\" helper to consumes the trailing `\\r\\n`.\n\nIn this cas","public_affected_ranges":["< 0.16.0"]}],"null_published_at":"2026-10-31T22:27:09.602Z","source_updated_at":"2026-10-27T16:31:16.000Z","source_disclosed_at":"2025-04-24T16:07:56.000Z","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":"2026-10-31T21:56:51.534Z"},{"id":"NVI-00009034","kind":"vulnerability","title":"h11 accepts some malformed Chunked-Encoding bodies","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-vqfr-h8mv-ghfj","CVE-2025-43859"],"plain_summary":"GitHub lists this reviewed advisory for h11. 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-832e3e9a017377158d7b5e07ea29ce68"],"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":"2026-10-27T16:31:16.000Z","value":"9.1 critical","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-832e3e9a017377158d7b5e07ea29ce68"}],"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-832e3e9a017377158d7b5e07ea29ce68","url":"https://github.com/advisories/GHSA-vqfr-h8mv-ghfj","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-vqfr-h8mv-ghfj","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T21:56:51.534Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-832e3e9a017377158d7b5e07ea29ce68"],"technology":"h11","known_exclusions":[],"conditions_summary":"### Impact\n\nA leniency in h11's parsing of line terminators in chunked-coding message bodies can lead to request smuggling vulnerabilities under certain conditions.\n\n### Details\n\nHTTP/1.1 Chunked-Encoding bodies are formatted as a sequence of \"chunks\", each of which consists of:\n\n- chunk length\n- `\\r\\n`\n- `length` bytes of content\n- `\\r\\n`\n\nIn versions of h11 up to 0.14.0, h11 instead parsed them as:\n\n- chunk length\n- `\\r\\n`\n- `length` bytes of content\n- any two bytes\n\ni.e. it did not validate that the trailing `\\r\\n` bytes were correct, and if you put 2 bytes of garbage there it would be accepted, instead of correctly rejecting the body as malformed.\n\nBy itself this is harmless. However, suppose you have a proxy or reverse-proxy that tries to analyze HTTP requests, and your proxy has a _different_ bug in parsing Chunked-Encoding, acting as if the format is:\n\n- chunk length\n- `\\r\\n`\n- `length` bytes of content\n- more bytes of content, as many as it takes until you find a `\\r\\n`\n\nFor example, pound had this bug -- it can happen if an implementer uses a generic \"read until end of line\" helper to consumes the trailing `\\r\\n`.\n\nIn this cas","public_affected_ranges":["< 0.16.0"]}],"null_published_at":"2026-10-31T22:13:31.268Z","source_updated_at":"2026-10-27T16:31:16.000Z","source_disclosed_at":"2025-04-24T16:07:56.000Z","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":"2026-10-31T21:56:51.534Z"}],"next_cursor":null,"snapshot_revision":"42594"}