The 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.
This issue affects bandit: from 1.4.0 onward.
Analysis and contextual insights are available on OpenCVE Cloud.
Vendor Workaround
Disable HTTP/2 with http_2_options: [enabled: false], which removes both vulnerable paths. Alternatively, terminate HTTP/2 at a reverse proxy that enforces its own send timeouts and speaks HTTP/1 to Bandit.
Tracking
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Wed, 14 Oct 2026 17:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. The 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. This issue affects bandit: from 1.4.0 onward. | |
| Title | HTTP/2 blocked-send deadlines reset on every WINDOW_UPDATE, letting a trickle pin stream processes indefinitely in Bandit | |
| First Time appeared |
Mtrudel
Mtrudel bandit |
|
| Weaknesses | CWE-400 | |
| CPEs | cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Mtrudel
Mtrudel bandit |
|
| References |
|
|
| Metrics |
cvssV4_0
|
Status: PUBLISHED
Assigner: EEF
Published:
Updated: 2026-10-14T16:54:46.484Z
Reserved: 2026-10-12T10:00:01.326Z
Link: CVE-2026-105659
No data.
Status : Received
Published: 2026-10-14T17:18:15.657
Modified: 2026-10-14T17:18:15.657
Link: CVE-2026-105659
No data.
OpenCVE Enrichment
No data.
-
CWE-400
Uncontrolled Resource Consumption