{"id":"CVE-2026-105659","title":"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","summary":"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 conn…","severity":"none","cwe":["CWE-400"],"published":"2026-10-14","updated":"2026-10-14","sourceUpdated":"2026-10-14T17:18:15.657","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-105659","references":[{"url":"https://cna.erlef.org/cves/CVE-2026-105659.html","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/mtrudel/bandit/commit/d88b21953c65061f21136ea76a89a4f95a2ac7a1","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/mtrudel/bandit/commit/fff06efe3be962b484bd4d3eb339372fda5a231f","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/mtrudel/bandit/security/advisories/GHSA-69m6-wcv4-rwcf","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-105659","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}],"tags":["nvd"],"ingestedAt":"2026-10-14T17:44:53.672Z","slug":"CVE-2026-105659","body":"## Overview\n\nUncontrolled 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}