CVE-2026-74836
Analyse NVD en cours
Allocation of Resources Without Limits or Throttling vulnerability in mtrudel bandit allows an unauthenticated remote attacker to pin an unbounded number of HTTP/2 stream processes indefinitely via connection-level flow control. When a stream's response body outruns the HTTP/2 connection-level send window (default 65,535 bytes, shared across all streams on the connection), Bandit.HTTP2.Connection queues the remaining bytes and a reply closure in pending_sends and the stream process blocks forever inside a synchronous call to the connection process. Nothing bounds that wait and nothing purges the queue: a client RST_STREAM for the blocked stream is delivered to its mailbox but never read while it is stuck inside the call, so cancelling frees nothing, and periodic PING frames keep the transport-level read timeout from ever firing. The equivalent block on the stream-level send window is already bounded at 15 seconds; the connection-level path had no such bound. Each stalled stream pins its process, Plug state, and any resource the Plug holds across the blocked write, such as a pooled upstream connection in a reverse-proxy Plug. The attacker chooses any endpoint whose response exceeds the connection window (common for most non-trivial payloads), grants a generous stream-level window so only the connection window limits it, and keeps the connection alive with periodic PINGs; the primitive is repeatable across streams and connections at the cost of one idle socket each. This issue affects bandit: from 0.3.4 before 1.12.5.
Ce que ça veut dire
- Exposition
- Exploitable à distance depuis le réseau, sans authentification et sans action de la victime.
- Impact
- Un attaquant peut mettre le service hors ligne.
- Faiblesse
- Des ressources sont allouées sans plafond : la saturation est atteignable par une simple répétition.
- Probabilité
- Le score EPSS reste bas : rien n’annonce une exploitation imminente, ce qui ne dispense pas de corriger.
À faireÀ intégrer au prochain cycle de correctifs. Commencer par les instances exposées à Internet.
Lecture automatique du vecteur CVSS, du type de faiblesse (CWE) et du score EPSS. La description technique ci-dessus reste celle publiée par le NIST, en anglais.