Chunk extensions accept bare LF and CR, enabling request smuggling in Bandit

{
  "id": "270dfaa2698671326989506e2fd13047f568d2ed2a66f90282f5faa6d2d64003",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-114216",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "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 proxy via a chunk extension that contains a bare LF. The 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. This issue affects bandit: from 1.12.4 before 1.14.0.",
    "evidence": "cve:CVE-2026-114216",
    "products": [
      {
        "name": {
          "value": "bandit",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      },
      {
        "name": {
          "value": "bandit",
          "evidence": "/containers/cna/affected/1/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-114216",
      "aliases": [
        "CVE-2026-114216"
      ],
      "metrics": [
        {
          "format": "CVSS",
          "cvssV4_0": {
            "Safety": "NOT_DEFINED",
            "version": "4.0",
            "Recovery": "NOT_DEFINED",
            "baseScore": 6.3,
            "Automatable": "NOT_DEFINED",
            "attackVector": "NETWORK",
            "baseSeverity": "MEDIUM",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "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",
            "providerUrgency": "NOT_DEFINED",
            "userInteraction": "NONE",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "privilegesRequired": "NONE",
            "subIntegrityImpact": "LOW",
            "vulnIntegrityImpact": "LOW",
            "subAvailabilityImpact": "NONE",
            "vulnAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "affected": [
        {
          "cpes": [
            "cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*"
          ],
          "repo": "https://github.com/mtrudel/bandit",
          "vendor": "mtrudel",
          "product": "bandit",
          "versions": [
            {
              "status": "affected",
              "version": "1.12.4",
              "lessThan": "1.14.0",
              "versionType": "semver"
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          ],
          "packageURL": "pkg:hex/bandit",
          "packageName": "bandit",
          "collectionURL": "https://repo.hex.pm",
          "defaultStatus": "unaffected"
        },
        {
          "cpes": [
            "cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*"
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          "repo": "https://github.com/mtrudel/bandit",
          "vendor": "mtrudel",
          "product": "bandit",
          "versions": [
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              "version": "c31e9e3c76dcbfc239a96eabed5341ced7885ae5",
              "lessThan": "220b9dfd27f9a21305be2afc75cbe585ddc24e7a",
              "versionType": "git"
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          "packageURL": "pkg:github/mtrudel/bandit",
          "packageName": "mtrudel/bandit",
          "collectionURL": "https://github.com",
          "defaultStatus": "unaffected"
        }
      ],
      "modified": "2026-10-26T15:35:51.933Z",
      "provider": "cve",
      "references": [
        "https://github.com/mtrudel/bandit/security/advisories/GHSA-w5wc-g2hc-g7m2",
        "https://cna.erlef.org/cves/CVE-2026-114216.html",
        "https://osv.dev/vulnerability/EEF-CVE-2026-114216",
        "https://github.com/mtrudel/bandit/commit/c31e9e3c76dcbfc239a96eabed5341ced7885ae5",
        "https://github.com/mtrudel/bandit/commit/220b9dfd27f9a21305be2afc75cbe585ddc24e7a"
      ],
      "provider_metadata": {
        "adp": [
          {
            "title": "CISA ADP Vulnrichment",
            "metrics": [
              {
                "other": {
                  "type": "ssvc",
                  "content": {
                    "id": "CVE-2026-114216",
                    "role": "CISA Coordinator",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "version": "2.0.3",
                    "timestamp": "2026-10-26T15:03:20.382433Z"
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        "cna": {
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          "shortName": "EEF",
          "dateUpdated": "2026-10-26T13:30:41.225Z"
        }
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    },
    "related_cves": [
      {
        "value": "CVE-2026-114216",
        "evidence": "/cveMetadata/cveId"
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    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 316046,
  "published_at": "2026-10-26T13:30:41.225+00:00"
}