CVE-2026-114213: falha de alta gravidade em mtrudel bandit
WebSocket 1-byte continuation frames bypass `max_fragmented_message_size` in Bandit
Publicada em
Aviso por e-mail quando ela entrar no KEV, ganhar PoC pública ou subir de nota.
21Vexday Risk Score
Sem sinal de exploração. Nenhum artefato público de exploração conhecido até agora.
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
Produtos afetados
mtrudel · banditCVEs relacionadas — mtrudel bandit
No mesmo produto, das mais perigosas para as 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%
Referências
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