{"id":"UBUNTU-CVE-2026-110499","details":"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.","modified":"2026-10-28T20:17:05.056056990Z","published":"2026-10-26T14:16:00Z","upstream":["CVE-2026-110499"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-110499"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-110499"},{"type":"REPORT","url":"https://cna.erlef.org/cves/cve-2026-110499.html"},{"type":"REPORT","url":"https://github.com/mtrudel/bandit/commit/0e68313fab9d204257ebad5c447e4cd9cea8e0ea"},{"type":"REPORT","url":"https://github.com/mtrudel/bandit/commit/220b9dfd27f9a21305be2afc75cbe585ddc24e7a"},{"type":"REPORT","url":"https://github.com/mtrudel/bandit/security/advisories/ghsa-47x4-3fxf-82fr"},{"type":"REPORT","url":"https://hex.pm/packages/bandit"},{"type":"REPORT","url":"https://github.com"},{"type":"REPORT","url":"https://github.com/mtrudel/bandit"},{"type":"REPORT","url":"https://repo.hex.pm"},{"type":"REPORT","url":"https://github.com/cveproject/cvelistv5/tree/main/cves/2026/110xxx/cve-2026-110499.json"},{"type":"REPORT","url":"https://nvd.nist.gov/vuln/detail/cve-2026-110499"},{"type":"REPORT","url":"https://osv.dev/vulnerability/eef-cve-2026-110499"}],"affected":[{"package":{"name":"bandit","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/bandit?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.13.2-1","0.13.2-3"],"ecosystem_specific":{"binaries":[{"binary_name":"bandit","binary_version":"0.13.2-3"},{"binary_name":"python-bandit","binary_version":"0.13.2-3"},{"binary_name":"python3-bandit","binary_version":"0.13.2-3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-110499.json"}},{"package":{"name":"bandit","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/bandit?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.0-0ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_name":"bandit","binary_version":"1.4.0-0ubuntu2"},{"binary_version":"1.4.0-0ubuntu2","binary_name":"python-bandit"},{"binary_name":"python3-bandit","binary_version":"1.4.0-0ubuntu2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-110499.json"}},{"package":{"name":"bandit","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/bandit?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.5.1-3","1.6.2-1"],"ecosystem_specific":{"binaries":[{"binary_name":"bandit","binary_version":"1.6.2-1"},{"binary_name":"python3-bandit","binary_version":"1.6.2-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-110499.json"}},{"package":{"name":"bandit","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/bandit?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6.2-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1.6.2-1","binary_name":"bandit"},{"binary_name":"python3-bandit","binary_version":"1.6.2-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-110499.json"}},{"package":{"name":"bandit","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/bandit?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6.2-3"],"ecosystem_specific":{"binaries":[{"binary_version":"1.6.2-3","binary_name":"bandit"},{"binary_name":"python3-bandit","binary_version":"1.6.2-3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-110499.json"}},{"package":{"name":"bandit","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/bandit?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.7.10-3","1.9.4-1"],"ecosystem_specific":{"binaries":[{"binary_name":"bandit","binary_version":"1.9.4-1"},{"binary_name":"python3-bandit","binary_version":"1.9.4-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-110499.json"}},{"package":{"name":"bandit","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/bandit?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.7.10-2","1.7.10-3"],"ecosystem_specific":{"binaries":[{"binary_version":"1.7.10-3","binary_name":"bandit"},{"binary_version":"1.7.10-3","binary_name":"python3-bandit"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-110499.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V4","score":"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"},{"type":"CVSS_V4","score":"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"},{"type":"Ubun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