{"id":"CVE-2026-105659","revision":"5f9c5177ddf444a084296c6d3628aaa5","records":[{"revision":"5f9c5177ddf444a084296c6d3628aaa5","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-105659","aliases":[],"title":"HTTP/2 blocked-send deadlines reset on every WINDOW_UPDATE, letting a trickle pin stream processes indefinitely in Bandit","description":"Uncontrolled Resource Consumption vulnerability in mtrudel bandit allows an unauthenticated remote attacker to pin HTTP/2 stream processes indefinitely via a trickle of small WINDOW_UPDATE frames. A stream whose response outruns the connection or stream send window blocks until the peer grants more window, and each block carries a 15 second deadline. Both deadlines restart whenever the peer makes partial progress. Bandit.HTTP2.Connection.finish_data/5 re-queues a partially advanced send in pending_sends with a fresh expires_at, so every WINDOW_UPDATE on stream 0, and every SETTINGS frame, resets the clock. Bandit.HTTP2.Stream.send_data/3 recurses on each stream WINDOW_UPDATE and re-arms a fresh after read_timeout. A peer that grants a few bytes every few seconds keeps the blocked stream process, its Plug state and any resource it holds mid-response alive for as long as it keeps dripping, and repeats this across streams and connections to exhaust server processes and memory.\n\nThe two paths are independent. The stream-level block is reached on its own by widening the connection window with a large WINDOW_UPDATE on stream 0 and shrinking the per-stream window with a small SETTINGS_INITIAL_WINDOW_SIZE, so closing only the connection-level path leaves it exploitable.\n\nThis issue affects bandit: from 1.4.0 before 1.13.0.","state":0,"publishedAt":"2026-10-14T16:54:46.484+00:00","modifiedAt":"2026-10-16T20:07:01.914+00:00","affected":[{"ecosystem":"https://repo.hex.pm","name":"bandit","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"collectionURL\": \"https://repo.hex.pm\",\n                    \"cpes\": [\n                        \"cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*\"\n                    ],\n                    \"defaultStatus\": \"unaffected\",\n                    \"modules\": [\n                        \"'Elixir.Bandit.HTTP2.Connection'\",\n                        \"'Elixir.Bandit.HTTP2.Stream'\"\n                    ],\n                    \"packageName\": \"bandit\",\n                    \"packageURL\": \"pkg:hex/bandit\",\n                    \"product\": \"bandit\",\n                    \"programFiles\": [\n                        \"lib/bandit/http2/connection.ex\",\n                        \"lib/bandit/http2/stream.ex\"\n                    ],\n                    \"programRoutines\": [\n                        {\n                            \"name\": \"'Elixir.Bandit.HTTP2.Connection':finish_data/5\"\n                        },\n                        {\n                            \"name\": \"'Elixir.Bandit.HTTP2.Connection':do_pending_sends/2\"\n                        },\n                        {\n                            \"name\": \"'Elixir.Bandit.HTTP2.Connection':handle_frame/3\"\n                        },\n                        {\n                            \"name\": \"'Elixir.Bandit.HTTP2.Stream':send_data/3\"\n                        }\n                    ],\n                    \"repo\": \"https://github.com/mtrudel/bandit\",\n                    \"vendor\": \"mtrudel\",\n                    \"versions\": [\n                        {\n                            \"lessThan\": \"1.13.0\",\n                            \"status\": \"affected\",\n                            \"version\": \"1.4.0\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"},{"ecosystem":"https://github.com","name":"mtrudel/bandit","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"collectionURL\": \"https://github.com\",\n                    \"cpes\": [\n                        \"cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*\"\n                    ],\n                    \"defaultStatus\": \"unaffected\",\n                    \"modules\": [\n                        \"'Elixir.Bandit.HTTP2.Connection'\",\n                        \"'Elixir.Bandit.HTTP2.Stream'\"\n                    ],\n                    \"packageName\": \"mtrudel/bandit\",\n                    \"packageURL\": \"pkg:github/mtrudel/bandit\",\n                    \"product\": \"bandit\",\n                    \"programFiles\": [\n                        \"lib/bandit/http2/connection.ex\",\n                        \"lib/bandit/http2/stream.ex\"\n                    ],\n                    \"programRoutines\": [\n                        {\n                            \"name\": \"'Elixir.Bandit.HTTP2.Connection':finish_data/5\"\n                        },\n                        {\n                            \"name\": \"'Elixir.Bandit.HTTP2.Connection':do_pending_sends/2\"\n                        },\n                        {\n                            \"name\": \"'Elixir.Bandit.HTTP2.Connection':handle_frame/3\"\n                        },\n                        {\n                            \"name\": \"'Elixir.Bandit.HTTP2.Stream':send_data/3\"\n                        }\n                    ],\n                    \"repo\": \"https://github.com/mtrudel/bandit\",\n                    \"vendor\": \"mtrudel\",\n                    \"versions\": [\n                        {\n                            \"lessThan\": \"d88b21953c65061f21136ea76a89a4f95a2ac7a1\",\n                            \"status\": \"affected\",\n                            \"version\": \"fff06efe3be962b484bd4d3eb339372fda5a231f\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","score":8.7,"severity":"HIGH"}],"references":["https://github.com/mtrudel/bandit/security/advisories/GHSA-69m6-wcv4-rwcf","https://cna.erlef.org/cves/CVE-2026-105659.html","https://osv.dev/vulnerability/EEF-CVE-2026-105659","https://github.com/mtrudel/bandit/commit/fff06efe3be962b484bd4d3eb339372fda5a231f","https://github.com/mtrudel/bandit/commit/d88b21953c65061f21136ea76a89a4f95a2ac7a1"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-105659","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-105659","identifiers":["CVE-2026-105659"]},"retained":false,"historicalAffected":[]}],"coverage":[]}