Apache Traffic Server: HEAD requests carrying Content-Length or Transfer-Encoding enable request smuggling

{
  "id": "49798f41ff0f61b15699c49133acd3c3bdf8a7ab2bf3fc18f327ecec1c4ec27e",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-111809",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Apache Traffic Server: HEAD requests carrying Content-Length or Transfer-Encoding enable request smuggling",
    "summary": "Apache Traffic Server allows request smuggling via HEAD requests that carry Content-Length or Transfer-Encoding. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.",
    "evidence": "cve:CVE-2026-111809",
    "products": [
      {
        "name": {
          "value": "Apache Traffic Server",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-111809",
      "aliases": [
        "CVE-2026-111809"
      ],
      "metrics": [
        {
          "other": {
            "type": "Textual description of severity",
            "content": {
              "text": "moderate"
            }
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "format": "CVSS",
          "cvssV3_1": {
            "scope": "CHANGED",
            "version": "3.1",
            "baseScore": 9.3,
            "attackVector": "NETWORK",
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N",
            "integrityImpact": "HIGH",
            "userInteraction": "NONE",
            "attackComplexity": "LOW",
            "availabilityImpact": "NONE",
            "privilegesRequired": "NONE",
            "confidentialityImpact": "LOW"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "format": "CVSS",
          "cvssV4_0": {
            "Safety": "NOT_DEFINED",
            "version": "4.0",
            "Recovery": "NOT_DEFINED",
            "baseScore": 6.9,
            "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:H/SA:N",
            "exploitMaturity": "NOT_DEFINED",
            "providerUrgency": "NOT_DEFINED",
            "userInteraction": "NONE",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "privilegesRequired": "NONE",
            "subIntegrityImpact": "HIGH",
            "vulnIntegrityImpact": "LOW",
            "subAvailabilityImpact": "NONE",
            "vulnAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "affected": [
        {
          "vendor": "Apache Software Foundation",
          "product": "Apache Traffic Server",
          "versions": [
            {
              "status": "affected",
              "version": "8.0.0",
              "versionType": "semver",
              "lessThanOrEqual": "8.1.11"
            },
            {
              "status": "affected",
              "version": "9.0.0",
              "versionType": "semver",
              "lessThanOrEqual": "9.2.15"
            },
            {
              "status": "affected",
              "version": "10.0.0",
              "versionType": "semver",
              "lessThanOrEqual": "10.1.4"
            },
            {
              "status": "affected",
              "version": "10.2.0",
              "versionType": "semver"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ],
      "modified": "2026-10-28T01:34:23.820Z",
      "provider": "cve",
      "references": [
        "https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc"
      ],
      "provider_metadata": {
        "adp": [
          {
            "title": "CISA ADP Vulnrichment",
            "metrics": [
              {
                "other": {
                  "type": "ssvc",
                  "content": {
                    "id": "CVE-2026-111809",
                    "role": "CISA Coordinator",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "version": "2.0.3",
                    "timestamp": "2026-10-28T01:34:12.842103Z"
                  }
                }
              }
            ],
            "providerMetadata": {
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP",
              "dateUpdated": "2026-10-28T01:34:23.820Z"
            }
          }
        ],
        "cna": {
          "orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
          "shortName": "apache",
          "dateUpdated": "2026-10-21T19:16:16.439Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-111809",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 404500,
  "published_at": "2026-10-21T19:16:16.439+00:00"
}