CVE-2026-110499: falha de alta gravidade em mtrudel bandit
Client-chosen HPACK encoder table size is applied uncapped, growing per-connection state with every response in Bandit
Publicada em
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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 HTTP/2 implementation of mtrudel bandit allows an unauthenticated remote attacker to grow per-connection memory and CPU cost without bound via a large SETTINGS_HEADER_TABLE_SIZE. Bandit resizes its HPACK encoder table to whatever size the client advertises, up to 2^32-1 bytes, and indexes response headers into it. Because responses carry distinct values such as date or content-length, nothing is evicted and the table grows with every response for the life of the connection, while each lookup scans it linearly.
The SETTINGS handling in Bandit.HTTP2.Connection (lib/bandit/http2/connection.ex) passes remote_settings.header_table_size to HPAX.resize/2 with no server-side cap, and encode_headers encodes every response header as :store. Serving N responses on one connection therefore costs O(N²) CPU in the connection process.
This issue affects bandit: from 0.3.6 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
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Referências
https://cna.erlef.org/cves/CVE-2026-110499.htmlhttps://github.com/mtrudel/bandit/commit/0e68313fab9d204257ebad5c447e4cd9cea8e0eahttps://github.com/mtrudel/bandit/commit/220b9dfd27f9a21305be2afc75cbe585ddc24e7ahttps://github.com/mtrudel/bandit/security/advisories/GHSA-47x4-3fxf-82frhttps://osv.dev/vulnerability/EEF-CVE-2026-110499