{"id":"CVE-2026-111101","summary":"HTTP/1.1 chunked request bodies made of 1-byte chunks amplify memory use in Bandit","details":"Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/1.1 chunked body reader of mtrudel bandit allows an unauthenticated remote attacker to exhaust server memory and CPU via a request body made of many 1-byte chunks.\n\nThe chunked reader in lib/bandit/http1/socket.ex keeps every chunk as its own list cell and binary term until IO.iodata_to_binary/1 joins them, and nothing limits the number of chunks. The :length option of read_body/2 counts only data bytes, so tiny chunks cost far more memory than their payload: 48 MB of 1-byte chunks grew one handler process to about 500 MB and took about 6 s of CPU. The route does not need to read the body, because on keep-alive connections ensure_completed/1 drains unread bodies through the same reader.\n\nThis issue affects bandit: from 0.1.0 before 1.14.0.","aliases":["EEF-CVE-2026-111101","GHSA-jwh3-j29h-qfmw"],"modified":"2026-10-28T02:56:07.061624239Z","published":"2026-10-26T13:31:48.184Z","database_specific":{"cna_assigner":"EEF","cwe_ids":["CWE-770"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/111xxx/CVE-2026-111101.json"},"references":[{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-111101.html"},{"type":"WEB","url":"https://github.com"},{"type":"WEB","url":"https://osv.dev/vulnerability/EEF-CVE-2026-111101"},{"type":"WEB","url":"https://repo.hex.pm"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/111xxx/CVE-2026-111101.json"},{"type":"ADVISORY","url":"https://github.com/mtrudel/bandit/security/advisories/GHSA-jwh3-j29h-qfmw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-111101"},{"type":"FIX","url":"https://github.com/mtrudel/bandit/commit/220b9dfd27f9a21305be2afc75cbe585ddc24e7a"},{"type":"FIX","url":"https://github.com/mtrudel/bandit/commit/7201270c34b90f6c9e15c0386c2bb802c0c72ab4"},{"type":"PACKAGE","url":"https://github.com/mtrudel/bandit"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mtrudel/bandit","events":[{"introduced":"7201270c34b90f6c9e15c0386c2bb802c0c72ab4"},{"fixed":"220b9dfd27f9a21305be2afc75cbe585ddc24e7a"},{"introduced":"4c80fc838640c4dae4743a61494981c57d6eef00"},{"fixed":"220b9dfd27f9a21305be2afc75cbe585ddc24e7a"},{"fixed":"7201270c34b90f6c9e15c0386c2bb802c0c72ab4"}],"database_specific":{"extracted_events":[{"source":"AFFECTED_FIELD","strategy":"StandardRange","range":[{"introduced":"7201270c34b90f6c9e15c0386c2bb802c0c72ab4"},{"fixed":"220b9dfd27f9a21305be2afc75cbe585ddc24e7a"}]},{"range":[{"introduced":"0.1.0"},{"fixed":"1.14.0"}],"source":"AFFECTED_FIELD","strategy":"StandardRange"},{"source":"REFERENCES_COMMIT","range":[{"fixed":"7201270c34b90f6c9e15c0386c2bb802c0c72ab4"}]},{"source":"REFERENCES_COMMIT","range":[{"fixed":"220b9dfd27f9a21305be2afc75cbe585ddc24e7a"}]}]}}],"versions":["1.13.1","1.13.0","1.12.5","1.12.4","1.12.3","1.12.1","1.12.0","1.11.1","1.11.0","1.10.4","1.10.3","1.10.2","1.10.1","1.10.0","1.9.0","1.8.0","1.7.0","1.6.11","1.6.10","1.6.9","1.6.8","1.6.7","1.6.6","1.6.5","1.6.4","1.6.3","1.6.2","1.6.1","1.6.0","1.5.7","1.5.6","1.5.5","1.5.4","1.5.3","1.5.2","1.5.1","1.5.0","1.4.2","1.4.1","1.4.0","1.3.0","1.2.3","1.2.0","1.1.3","1.1.2","1.1.1","1.1.0","1.0.0","1.0.0-pre.18","1.0.0-pre.17","1.0.0-pre.16","1.0.0-pre.15","1.0.0-pre.14","1.0.0-pre.13","1.0.0-pre.12","1.0.0-pre.11","1.0.0-pre.10","1.0.0-pre.9","1.0.0-pre.8","1.0.0-pre.7","1.0.0-pre.6","1.0.0-pre.5","1.0.0-pre.4","1.0.0-pre.3","1.0.0-pre.2","1.0.0-pre.1","0.7.7","0.7.6","0.7.5","0.7.4","0.7.3","0.7.2","0.7.1","0.7.0","0.6.11","0.6.10","0.6.9","0.6.8","0.6.7","0.6.6","0.6.5","0.6.4","0.6.3","0.6.2","0.6.1","0.6.0","0.5.11","0.5.10","0.5.9","0.5.8","0.5.7","0.5.6","0.5.5","0.5.4","0.5.3","0.5.2","0.5.1","0.5.0","0.4.10","0.4.9","0.4.8","0.4.7","0.4.6","0.4.5","0.4.4","0.4.3","0.4.2","0.4.1","0.4.0","0.3.9","0.3.8","0.3.7","0.3.6","0.3.5","0.3.4","0.3.3","0.3.2","0.3.1","0.3.0","0.2.3","0.2.2","0.2.1","0.2.0","0.1.1","0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-111101.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"}]}