{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "2.2.0-alpha"
              },
              {
                "fixed": "2.2.2-alpha"
              },
              {
                "introduced": "0"
              },
              {
                "fixed": "2.1.13"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "df3ecad3a040fd6d4fad4287defe113395de6fd7"
            },
            {
              "fixed": "79ddfb460847999b807cba76d04e73891f29c6ee"
            },
            {
              "fixed": "10abb34b8dc3e1184de315dd261ce4b77563cda6"
            },
            {
              "fixed": "5119ceb00557bf007f9065709e852686f3c0bb6e"
            },
            {
              "fixed": "83ba67373032334559b82409db035dd8c3cc1660"
            },
            {
              "fixed": "ac38703b2d312200c4f967f02936af0118d384a0"
            }
          ],
          "repo": "https://github.com/libevent/libevent",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-q39v-w2g7-gr8j"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-444"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63382.json"
  },
  "details": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, the libevent evhttp parser in http.c inconsistently handles duplicate Transfer-Encoding headers, comma-separated Transfer-Encoding values, and bare line feeds in chunked framing. evhttp_find_header can select only the first header, evhttp_check_transfer_encoding_ was absent so the previous whole-string comparison fails to recognize valid lists ending in chunked, and evhttp_handle_chunked_read uses EVBUFFER_EOL_CRLF rather than EVBUFFER_EOL_CRLF_STRICT, accepting bare LF chunk terminators. When libevent is deployed behind a proxy that frames the same request differently, an unauthenticated remote attacker can desynchronize request boundaries and smuggle a second request, potentially bypassing access controls or poisoning caches. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.",
  "id": "CVE-2026-63382",
  "modified": "2026-08-22T03:30:53.398297253Z",
  "published": "2026-08-20T17:51:15.156Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"
    },
    {
      "type": "WEB",
      "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63382.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/libevent/libevent/security/advisories/GHSA-q39v-w2g7-gr8j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63382"
    },
    {
      "type": "FIX",
      "url": "https://github.com/libevent/libevent/commit/10abb34b8dc3e1184de315dd261ce4b77563cda6"
    },
    {
      "type": "FIX",
      "url": "https://github.com/libevent/libevent/commit/5119ceb00557bf007f9065709e852686f3c0bb6e"
    },
    {
      "type": "FIX",
      "url": "https://github.com/libevent/libevent/commit/83ba67373032334559b82409db035dd8c3cc1660"
    },
    {
      "type": "FIX",
      "url": "https://github.com/libevent/libevent/commit/ac38703b2d312200c4f967f02936af0118d384a0"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "libevent evhttp: Multiple HTTP Parser Bugs Enable Request Smuggling"
}