CVE-2026-114213: fallo de gravedad alta en mtrudel bandit
WebSocket 1-byte continuation frames bypass `max_fragmented_message_size` in Bandit
Publicada el
Aviso por correo cuando entre en el KEV, tenga PoC pública o suba de nota.
21Vexday Risk Score
Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.
ssvc Trackcvss 8.7epss 0.6%
Allocation of Resources Without Limits or Throttling vulnerability in the WebSocket fragment reassembly of mtrudel bandit allows an unauthenticated remote attacker to exhaust server memory via a fragmented message made of many 1-byte continuation frames.
Bandit.WebSocket.Connection checks max_fragmented_message_size against the payload bytes received, but keeps every non-final continuation frame as a new list cell around its own binary, and nothing limits the number of fragments. A 1-byte fragment costs 7 bytes on the wire but about 150 to 170 bytes of server memory, so one connection can hold about 150 times the configured limit, roughly 1.2 to 1.4 GB at the default 8 MB. Ping frames between fragments keep the connection alive past the idle timeout.
This issue affects bandit: from 1.11.0 before 1.14.0.
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
Productos afectados
mtrudel · banditCVEs relacionadas — mtrudel bandit
En el mismo producto, de las más peligrosas a las menos.
CVE-2026-39804HIGHWebSocket permessage-deflate inflate has no output-size cap in banditEPSS 0.8%CVE-2026-75484MEDIUMHTTP/2 header field values containing CR, LF or NUL are passed to the application unvalidated in BanditEPSS 0.7%CVE-2026-42786HIGHWebSocket fragmented message reassembly unbounded in banditEPSS 0.6%CVE-2026-39803HIGHHTTP/1 chunked body reader ignores length cap in banditEPSS 0.6%CVE-2026-74836HIGHHTTP/2 connection-window starvation pins Plug processes indefinitely in BanditEPSS 0.6%CVE-2026-39806HIGHHTTP/1 chunked decoder infinite loop on requests with trailer fields in banditEPSS 0.6%
Referencias
https://cna.erlef.org/cves/CVE-2026-114213.htmlhttps://github.com/mtrudel/bandit/commit/21612c7c7b1ce43eccd36d3af3a2299d23513667https://github.com/mtrudel/bandit/commit/220b9dfd27f9a21305be2afc75cbe585ddc24e7ahttps://github.com/mtrudel/bandit/security/advisories/GHSA-cpx7-qf6w-jc63https://osv.dev/vulnerability/EEF-CVE-2026-114213