{
  "cveId": "CVE-2026-55204",
  "url": "https://patchblox.com/security/cve/CVE-2026-55204",
  "summary": "CVE-2026-55204 is fixed in 4 products on 1 platform, first by RHSA-2026:55800, released June 18, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "HAProxy - NULL Pointer Dereference in hpack_dht_insert Function",
  "description": "HAProxy through  3.4.0, fixed in commit 9a6d1fe, contains a null pointer dereference vulnerability in hpack_dht_insert() within src/hpack-tbl.c that fails to validate the return value of hpack_dht_defrag() when the memory pool is exhausted. An attacker can trigger HPACK dynamic table insertions under memory pressure to dereference a NULL pointer and crash HAProxy worker processes, causing denial of service.",
  "published": "2026-06-18T16:05:52Z",
  "severity": "Important",
  "cvss": 7.5,
  "cvssVector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N",
  "cwe": "NULL Pointer Dereference",
  "epss": 0.00484,
  "epssPercentile": 0.41955,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55204",
  "fixes": [
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "Debian 14",
      "fixedVersion": "3.2.20-1",
      "fix": "DEBIAN-CVE-2026-55204",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-55204",
      "released": "2026-06-29T14:19:49Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "RHEL 10",
      "fixedVersion": "3.0.5-4.el10_0.3",
      "fix": "RHSA-2026:55800",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-55800",
      "released": "2026-06-18T16:05:52Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "RHEL 8",
      "fixedVersion": "0:1.8.27-5.el8_10.2",
      "fix": "RHSA-2026:55859",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-55859",
      "released": "2026-08-19T23:17:39Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "RHEL 9",
      "fixedVersion": "0:2.8.14-3.el9_8.2",
      "fix": "RHSA-2026:55772",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-55772",
      "released": "2026-08-19T23:18:54Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "2.4.30-0ubuntu0.22.04.2",
      "fix": "haproxy 2.4.30-0ubuntu0.22.04.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-haproxy-2.4.30-0ubuntu0.22.04.2",
      "released": "2026-06-24T14:07:38Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "Ubuntu 24.04.5 LTS (noble)",
      "fixedVersion": "2.8.16-0ubuntu0.24.04.3",
      "fix": "haproxy 2.8.16-0ubuntu0.24.04.3",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-noble-haproxy-2.8.16-0ubuntu0.24.04.3",
      "released": "2026-06-24T14:07:41Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "Ubuntu 25.10 (questing)",
      "fixedVersion": "3.0.12-0ubuntu0.25.10.5",
      "fix": "haproxy 3.0.12-0ubuntu0.25.10.5",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-questing-haproxy-3.0.12-0ubuntu0.25.10.5",
      "released": "2026-06-24T14:07:44Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "3.2.9-1ubuntu2.2",
      "fix": "haproxy 3.2.9-1ubuntu2.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-haproxy-3.2.9-1ubuntu2.2",
      "released": "2026-06-18T17:00:00Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "almalinux 10",
      "fixedVersion": "3.0.5-6.el10_2.2",
      "fix": "ALSA-2026:55679",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55679",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "almalinux 8",
      "fixedVersion": "1.8.27-5.el8_10.2",
      "fix": "ALSA-2026:55859",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55859",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "almalinux 9",
      "fixedVersion": "2.8.14-3.el9_8.2",
      "fix": "ALSA-2026:55772",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55772",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "amzn 2023",
      "fixedVersion": "3.0.23-2.amzn2023.0.1",
      "fix": "ALAS2023-2026-1915",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1915",
      "released": "2026-07-06T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "ol 10",
      "fixedVersion": "0:3.0.5-6.el10_2.2",
      "fix": "ELSA-2026-55679",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55679",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "ol 8",
      "fixedVersion": "0:1.8.27-5.el8_10.2",
      "fix": "ELSA-2026-55859",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55859",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "ol 9",
      "fixedVersion": "0:2.8.14-3.el9_8.2",
      "fix": "ELSA-2026-55772",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55772",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "3.2.21\u002Bgit0.dbe43be37-160000.1.1",
      "fix": "OPENSUSE-SU-2026:21245-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21245-1",
      "released": "2026-07-07T10:11:42Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "rocky 10",
      "fixedVersion": "0:3.0.5-6.el10_2.2",
      "fix": "RLSA-2026:55679",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2026-55679",
      "released": "2026-08-18T12:07:31Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "rocky 8",
      "fixedVersion": "0:1.8.27-5.el8_10.2",
      "fix": "RLSA-2026:55859",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2026-55859",
      "released": "2026-08-18T06:01:20Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "rocky 9",
      "fixedVersion": "0:2.8.14-3.el9_8.2",
      "fix": "RLSA-2026:55772",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2026-55772",
      "released": "2026-08-18T06:04:25Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "sles 15.6",
      "fixedVersion": "2.8.11\u002Bgit0.01c1056a4-150600.3.15.1",
      "fix": "SUSE-SU-2026:2652-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-2652-1",
      "released": "2026-06-26T12:21:05Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "sles 15.7",
      "fixedVersion": "2.8.11\u002Bgit0.01c1056a4-150600.3.15.1",
      "fix": "SUSE-SU-2026:2652-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-2652-1",
      "released": "2026-06-26T12:21:05Z"
    },
    {
      "platform": "linux",
      "product": "haproxy",
      "release": "sles 16.0",
      "fixedVersion": "3.2.21\u002Bgit0.dbe43be37-160000.1.1",
      "fix": "SUSE-SU-2026:22557-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-22557-1",
      "released": "2026-07-07T10:14:15Z"
    },
    {
      "platform": "linux",
      "product": "haproxy-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "3.0.23-2.amzn2023.0.1",
      "fix": "ALAS2023-2026-1915",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1915",
      "released": "2026-07-06T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "haproxy-debugsource",
      "release": "amzn 2023",
      "fixedVersion": "3.0.23-2.amzn2023.0.1",
      "fix": "ALAS2023-2026-1915",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-1915",
      "released": "2026-07-06T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "vim-haproxy",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "2.4.30-0ubuntu0.22.04.2",
      "fix": "vim-haproxy 2.4.30-0ubuntu0.22.04.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-vim-haproxy-2.4.30-0ubuntu0.22.04.2",
      "released": "2026-06-24T14:07:38Z"
    },
    {
      "platform": "linux",
      "product": "vim-haproxy",
      "release": "Ubuntu 24.04.5 LTS (noble)",
      "fixedVersion": "2.8.16-0ubuntu0.24.04.3",
      "fix": "vim-haproxy 2.8.16-0ubuntu0.24.04.3",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-noble-vim-haproxy-2.8.16-0ubuntu0.24.04.3",
      "released": "2026-06-24T14:07:41Z"
    },
    {
      "platform": "linux",
      "product": "vim-haproxy",
      "release": "Ubuntu 25.10 (questing)",
      "fixedVersion": "3.0.12-0ubuntu0.25.10.5",
      "fix": "vim-haproxy 3.0.12-0ubuntu0.25.10.5",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-questing-vim-haproxy-3.0.12-0ubuntu0.25.10.5",
      "released": "2026-06-24T14:07:44Z"
    },
    {
      "platform": "linux",
      "product": "vim-haproxy",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "3.2.9-1ubuntu2.2",
      "fix": "vim-haproxy 3.2.9-1ubuntu2.2",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-vim-haproxy-3.2.9-1ubuntu2.2",
      "released": "2026-06-18T17:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}