{"id":"CVE-2026-105659","summary":"HTTP/2 blocked-send deadlines reset on every WINDOW_UPDATE, letting a trickle pin stream processes indefinitely in Bandit","details":"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 onward.","aliases":["EEF-CVE-2026-105659","GHSA-69m6-wcv4-rwcf"],"modified":"2026-10-15T02:47:18.416646955Z","published":"2026-10-14T16:54:46.484Z","database_specific":{"cna_assigner":"EEF","cwe_ids":["CWE-400"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/105xxx/CVE-2026-105659.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"1.4.0"},{"fixed":"*"}]}]},"references":[{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-105659.html"},{"type":"WEB","url":"https://github.com"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/105xxx/CVE-2026-105659.json"},{"type":"PACKAGE","url":"https://github.com/mtrudel/bandit"},{"type":"FIX","url":"https://github.com/mtrudel/bandit/commit/d88b21953c65061f21136ea76a89a4f95a2ac7a1"},{"type":"FIX","url":"https://github.com/mtrudel/bandit/commit/fff06efe3be962b484bd4d3eb339372fda5a231f"},{"type":"ADVISORY","url":"https://github.com/mtrudel/bandit/security/advisories/GHSA-69m6-wcv4-rwcf"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-105659"},{"type":"WEB","url":"https://osv.dev/vulnerability/EEF-CVE-2026-105659"},{"type":"WEB","url":"https://repo.hex.pm"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mtrudel/bandit","events":[{"introduced":"fff06efe3be962b484bd4d3eb339372fda5a231f"},{"fixed":"d88b21953c65061f21136ea76a89a4f95a2ac7a1"}]}],"versions":["1.12.5","1.12.4","1.12.3","1.12.1","1.12.0","1.11.1","1.11.0","1.10.4","1.10.3","1.10.2","1.10.1","1.10.0","1.9.0","1.8.0","1.7.0","1.6.11","1.6.10","1.6.9","1.6.8","1.6.7","1.6.6","1.6.5","1.6.4","1.6.3","1.6.2","1.6.1","1.6.0","1.5.7","1.5.6","1.5.5","1.5.4","1.5.3","1.5.2","1.5.1","1.5.0","1.4.2","1.4.1","1.4.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-105659.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}