CVE-2026-109584highCWE-409

CVE-2026-109584: falha de alta gravidade em mtrudel bandit

HTTP/2 cookie crumb join expands a small HPACK header block into an unbounded allocation in Bandit

Publicada em

Seguir esta CVE+ Monitorar bandit+ Monitorar bandit

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%
Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in the HTTP/2 implementation of mtrudel bandit allows an unauthenticated remote attacker to exhaust server memory via a small HPACK-compressed HEADERS block. The block stores one large cookie value in the HPACK dynamic table and then references it tens of thousands of times with 1-byte indexed fields. In the reporter's run, a 49 KB block made a server with default settings allocate a 183 MB cookie binary before any application code ran, and every concurrent stream can repeat the cost. Bandit.HTTP2.Connection caps only the compressed block (max_header_block_size), and its check of the decoded list against max_header_list_size never fires because that setting defaults to :infinity. combine_cookie_crumbs/1 in lib/bandit/http2/stream.ex then joins every crumb into one binary. This issue affects bandit: from 0.3.3 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 · bandit
CVEs 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%