{"id":"CVE-2026-114216","title":"Chunk extensions accept bare LF and CR, enabling request smuggling in Bandit","summary":"Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in the HTTP/1.1 chunked body reader of mtrudel bandit allows an unauthenticated remote attacker to smuggle a second request past a front-end p…","severity":"medium","cvss":6.3,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N","cvssSource":"cna","cwe":["CWE-444"],"vendor":"mtrudel","product":"bandit","affected":["bandit >= 1.12.4 < 1.14.0","mtrudel/bandit >= c31e9e3c76dcbfc239a96eabed5341ced7885ae5 < 220b9dfd27f9a21305be2afc75cbe585ddc24e7a"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-26T15:03:20.382433Z"},"published":"2026-10-26","updated":"2026-10-26","sourceUpdated":"2026-10-26T15:35:51.933Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-114216","references":[{"url":"https://github.com/mtrudel/bandit/security/advisories/GHSA-w5wc-g2hc-g7m2","label":"Chunk extensions accept bare LF and CR, enabling request smuggling in Bandit"},{"url":"https://cna.erlef.org/cves/CVE-2026-114216.html","label":"EEF CNA record for CVE-2026-114216"},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-114216","label":"OSV record EEF-CVE-2026-114216"},{"url":"https://github.com/mtrudel/bandit/commit/c31e9e3c76dcbfc239a96eabed5341ced7885ae5","label":"Introducing commit c31e9e3 in mtrudel/bandit"},{"url":"https://github.com/mtrudel/bandit/commit/220b9dfd27f9a21305be2afc75cbe585ddc24e7a","label":"Fix commit 220b9df in mtrudel/bandit"}],"tags":["cve.org"],"ingestedAt":"2026-10-26T14:27:31.829Z","slug":"CVE-2026-114216","body":"## Overview\n\nInconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in the HTTP/1.1 chunked body reader of mtrudel bandit allows an unauthenticated remote attacker to smuggle a second request past a front-end proxy via a chunk extension that contains a bare LF.\n\nThe chunked reader in lib/bandit/http1/socket.ex takes the chunk-size line to be everything up to the first CRLF and discards everything after ; without checking it against the RFC 9112 chunk-ext grammar, so bare LF, bare CR and other control bytes pass. A proxy that ends the size line at a bare LF reads 2;\\nxx\\r\\n40\\r\\n... as one request whose second chunk holds a GET /admin, while Bandit ends the body early and dispatches GET /admin as a separate pipelined request. Deployments without such a proxy in front of Bandit are not affected.\n\nThis issue affects bandit: from 1.12.4 before 1.14.0.\n\n## Affected\n\n- `bandit >= 1.12.4 < 1.14.0`\n- `mtrudel/bandit >= c31e9e3c76dcbfc239a96eabed5341ced7885ae5 < 220b9dfd27f9a21305be2afc75cbe585ddc24e7a`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n### Workarounds\n\nWhere the front-end proxy can reach Bandit over HTTP/2, disable HTTP/1 with http_1_options: [enabled: false], so that the chunked body reader never runs.","depth":"sunlit","depthScore":35,"depthScoreParts":{"impact":34.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}