{
  "cveId": "CVE-2026-63379",
  "url": "https://patchblox.com/security/cve/CVE-2026-63379",
  "summary": "CVE-2026-63379 is fixed in 5 products on 1 platform, first by DEBIAN-CVE-2026-63379, released August 21, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "Libevent: HTTP Header smuggling",
  "description": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent processes chunked HTTP trailers in http.c through evhttp_read_trailer and merges them into request headers. The fix introduces evhttp_parse_headers_impl_ and a temporary trailer header list. An unauthenticated remote attacker can place security-sensitive fields in trailers so that an upstream proxy and the libevent application interpret different effective headers, enabling header smuggling, authorization bypass, proxy-header spoofing, or cache poisoning. The fix parses trailers into a temporary header list and discards them instead of merging them into req-\u003Einput_headers. This issue is fixed in versions 2.1.13 and 2.2.2-alpha.",
  "published": "2026-08-20T17:55:00Z",
  "severity": "Moderate",
  "cvss": 8.6,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H",
  "cwe": "Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)",
  "epss": 0.00518,
  "epssPercentile": 0.44335,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63379",
  "fixes": [
    {
      "platform": "linux",
      "product": "libevent",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "2.1.12-stable-8\u002Bdeb12u1",
      "fix": "DEBIAN-CVE-2026-63379",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-63379",
      "released": "2026-08-21T23:37:15Z"
    },
    {
      "platform": "linux",
      "product": "libevent",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "2.1.13-stable-1~deb13u1",
      "fix": "DEBIAN-CVE-2026-63379",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-63379",
      "released": "2026-08-21T23:37:15Z"
    },
    {
      "platform": "linux",
      "product": "libevent",
      "release": "Debian 14",
      "fixedVersion": "2.1.13-stable-1",
      "fix": "DEBIAN-CVE-2026-63379",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-63379",
      "released": "2026-08-21T23:37:15Z"
    },
    {
      "platform": "linux",
      "product": "libevent",
      "release": "Fedora 43",
      "fixedVersion": "2.1.13-1.fc43",
      "fix": "FEDORA-2026-728DD9F704",
      "url": "https://patchblox.com/security/fix/linux/fedora-2026-728dd9f704",
      "released": "2026-09-07T14:19:40Z"
    },
    {
      "platform": "linux",
      "product": "libevent",
      "release": "RHEL 10",
      "fixedVersion": "2.1.13-1.el10_2",
      "fix": "RHSA-2026:67909",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-67909",
      "released": "2026-09-17T18:11:06Z"
    },
    {
      "platform": "linux",
      "product": "libevent",
      "release": "RHEL 9",
      "fixedVersion": "0:2.1.13-1.el9_8",
      "fix": "RHSA-2026:67910",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-67910",
      "released": "2026-09-19T18:32:55Z"
    },
    {
      "platform": "linux",
      "product": "libevent",
      "release": "almalinux 10",
      "fixedVersion": "2.1.13-1.el10_2",
      "fix": "ALSA-2026:67909",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-67909",
      "released": "2026-09-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libevent",
      "release": "almalinux 9",
      "fixedVersion": "2.1.13-1.el9_8",
      "fix": "ALSA-2026:67910",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-67910",
      "released": "2026-09-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libevent",
      "release": "ol 10",
      "fixedVersion": "0:2.1.13-1.el10_2",
      "fix": "ELSA-2026-67909",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-67909",
      "released": "2026-09-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libevent",
      "release": "ol 9",
      "fixedVersion": "0:2.1.13-1.el9_8",
      "fix": "ELSA-2026-67910",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-67910",
      "released": "2026-09-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libevent",
      "release": "rocky 10",
      "fixedVersion": "0:2.1.13-1.el10_2",
      "fix": "RLSA-2026:67909",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2026-67909",
      "released": "2026-09-17T12:09:45Z"
    },
    {
      "platform": "linux",
      "product": "libevent",
      "release": "rocky 9",
      "fixedVersion": "0:2.1.13-1.el9_8",
      "fix": "RLSA-2026:67910",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2026-67910",
      "released": "2026-09-17T06:06:39Z"
    },
    {
      "platform": "linux",
      "product": "libevent-debuginfo",
      "release": "Fedora 43",
      "fixedVersion": "2.1.13-1.fc43",
      "fix": "FEDORA-2026-728DD9F704",
      "url": "https://patchblox.com/security/fix/linux/fedora-2026-728dd9f704",
      "released": "2026-09-07T14:19:40Z"
    },
    {
      "platform": "linux",
      "product": "libevent-debugsource",
      "release": "Fedora 43",
      "fixedVersion": "2.1.13-1.fc43",
      "fix": "FEDORA-2026-728DD9F704",
      "url": "https://patchblox.com/security/fix/linux/fedora-2026-728dd9f704",
      "released": "2026-09-07T14:19:40Z"
    },
    {
      "platform": "linux",
      "product": "libevent-devel",
      "release": "Fedora 43",
      "fixedVersion": "2.1.13-1.fc43",
      "fix": "FEDORA-2026-728DD9F704",
      "url": "https://patchblox.com/security/fix/linux/fedora-2026-728dd9f704",
      "released": "2026-09-07T14:19:40Z"
    },
    {
      "platform": "linux",
      "product": "libevent-devel",
      "release": "RHEL 9",
      "fixedVersion": "0:2.1.13-1.el9_8",
      "fix": "RHSA-2026:67910",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-67910",
      "released": "2026-09-19T18:32:55Z"
    },
    {
      "platform": "linux",
      "product": "libevent-devel",
      "release": "almalinux 10",
      "fixedVersion": "2.1.13-1.el10_2",
      "fix": "ALSA-2026:67909",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-67909",
      "released": "2026-09-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libevent-devel",
      "release": "almalinux 9",
      "fixedVersion": "2.1.13-1.el9_8",
      "fix": "ALSA-2026:67910",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-67910",
      "released": "2026-09-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libevent-devel",
      "release": "ol 10",
      "fixedVersion": "0:2.1.13-1.el10_2",
      "fix": "ELSA-2026-67909",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-67909",
      "released": "2026-09-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libevent-devel",
      "release": "ol 9",
      "fixedVersion": "0:2.1.13-1.el9_8",
      "fix": "ELSA-2026-67910",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-67910",
      "released": "2026-09-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libevent-doc",
      "release": "Fedora 43",
      "fixedVersion": "2.1.13-1.fc43",
      "fix": "FEDORA-2026-728DD9F704",
      "url": "https://patchblox.com/security/fix/linux/fedora-2026-728dd9f704",
      "released": "2026-09-07T14:19:40Z"
    },
    {
      "platform": "linux",
      "product": "libevent-doc",
      "release": "RHEL 9",
      "fixedVersion": "0:2.1.13-1.el9_8",
      "fix": "RHSA-2026:67910",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-67910",
      "released": "2026-09-19T18:32:55Z"
    },
    {
      "platform": "linux",
      "product": "libevent-doc",
      "release": "almalinux 10",
      "fixedVersion": "2.1.13-1.el10_2",
      "fix": "ALSA-2026:67909",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-67909",
      "released": "2026-09-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libevent-doc",
      "release": "almalinux 9",
      "fixedVersion": "2.1.13-1.el9_8",
      "fix": "ALSA-2026:67910",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-67910",
      "released": "2026-09-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libevent-doc",
      "release": "ol 10",
      "fixedVersion": "0:2.1.13-1.el10_2",
      "fix": "ELSA-2026-67909",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-67909",
      "released": "2026-09-16T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libevent-doc",
      "release": "ol 9",
      "fixedVersion": "0:2.1.13-1.el9_8",
      "fix": "ELSA-2026-67910",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-67910",
      "released": "2026-09-16T00:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T13:31:49Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}