{"id":"UBUNTU-CVE-2026-113436","details":"Inefficient Algorithmic Complexity vulnerability in the header integer parser of mtrudel bandit allows an unauthenticated remote attacker to consume server CPU via a content-length value or a Host or :authority port made of thousands of digits. Bandit.Headers.parse_integer/2 in lib/bandit/headers.ex builds the number one digit at a time with no limit on the digit count, allocating a new bignum at each step, so one value costs time quadratic in its length. It runs on raw request input over HTTP/1 and HTTP/2, before any range check. Over HTTP/2, a 4,000-digit value can be stored once in the HPACK dynamic table and re-sent on each new stream for about one byte: 124 KB of traffic kept the server busy for 27.9 s. This issue affects bandit: from 1.0.0-pre.7 before 1.14.0.","modified":"2026-10-28T20:15:44.975590222Z","published":"2026-10-26T14:16:00Z","upstream":["CVE-2026-113436"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-113436"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-113436"},{"type":"REPORT","url":"https://cna.erlef.org/cves/cve-2026-113436.html"},{"type":"REPORT","url":"https://github.com/mtrudel/bandit/commit/220b9dfd27f9a21305be2afc75cbe585ddc24e7a"},{"type":"REPORT","url":"https://github.com/mtrudel/bandit/commit/e0c8c0c30af9b0f57d8aafac37ddd9294363a8be"},{"type":"REPORT","url":"https://github.com/mtrudel/bandit/security/advisories/ghsa-29cr-8477-rg6r"},{"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/2026/113xxx/cve-2026-113436.json"},{"type":"REPORT","url":"https://nvd.nist.gov/vuln/detail/cve-2026-113436"},{"type":"REPORT","url":"https://osv.dev/vulnerability/eef-cve-2026-113436"}],"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_version":"0.13.2-3","binary_name":"python3-bandit"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-113436.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-2026-113436.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_version":"1.6.2-1","binary_name":"python3-bandit"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-113436.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_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-2026-113436.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-2026-113436.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-2026-113436.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_name":"python3-bandit","binary_version":"1.7.10-3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-113436.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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