{
  "cveId": "CVE-2026-55973",
  "url": "https://patchblox.com/security/cve/CVE-2026-55973",
  "summary": "CVE-2026-55973 is fixed in 9 products on 1 platform, first by DEBIAN-CVE-2026-55973, released July 28, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "\u0027dns-error-reporting: yes\u0027 leads to stack buffer overflow",
  "description": "In NLnet Labs Unbound 1.23.0 up to and including 1.25.1, when \u0027dns-error-reporting: yes\u0027 is set, the EDNS Report-Channel option (code 18) from the last upstream response is read and uses the option\u0027s length as the length of the agent domain. When a domain name check is performed on the agent domain, the returned lenght is not used and if the agent domain is followed by garbage, those bytes are moved onto the tail of the synthetic \u0027_er.\u0027 report query name. That query name is later used in the iterator via a subquery to send out the DNS Error Report and when Unbound tries to walk that query name during \u0027find_closest_of_type()\u0027, it strips labels using the query name length rather than stopping at the embedded root, walks one byte past it, and feeds the first garbage byte to \u0027dname_query_hash()\u0027 as a label length writing over the stack variable \u0027labuf\u0027. One ordinary upstream response from a delegated zone the attacker controls is sufficient to terminate the daemon.",
  "published": "2026-07-22T00:00:00Z",
  "severity": "Moderate",
  "cvss": 8.6,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N",
  "cwe": "Improper Input Validation",
  "epss": 0.00281,
  "epssPercentile": 0.20663,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55973",
  "fixes": [
    {
      "platform": "linux",
      "product": "libunbound8",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "1.24.2-1ubuntu2.4",
      "fix": "libunbound8 1.24.2-1ubuntu2.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-libunbound8-1.24.2-1ubuntu2.4",
      "released": "2026-09-16T02:17:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-unbound",
      "release": "RHEL 9",
      "fixedVersion": "0:1.24.2-3.el9_8.4",
      "fix": "RHSA-2026:55841",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-55841",
      "released": "2026-08-19T23:18:54Z"
    },
    {
      "platform": "linux",
      "product": "python3-unbound",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "1.24.2-1ubuntu2.4",
      "fix": "python3-unbound 1.24.2-1ubuntu2.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-python3-unbound-1.24.2-1ubuntu2.4",
      "released": "2026-09-16T02:17:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-unbound",
      "release": "almalinux 10",
      "fixedVersion": "1.24.2-7.el10_2.4",
      "fix": "ALSA-2026:55892",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-unbound",
      "release": "almalinux 9",
      "fixedVersion": "1.24.2-3.el9_8.4",
      "fix": "ALSA-2026:55841",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55841",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-unbound",
      "release": "ol 10",
      "fixedVersion": "0:1.24.2-7.el10_2.4",
      "fix": "ELSA-2026-55892",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-unbound",
      "release": "ol 9",
      "fixedVersion": "0:1.24.2-3.el9_8.4",
      "fix": "ELSA-2026-55841",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55841",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "1.26.1-0\u002Bdeb13u1",
      "fix": "DEBIAN-CVE-2026-55973",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-55973",
      "released": "2026-07-28T14:13:38Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "Debian 14",
      "fixedVersion": "1.25.2-1",
      "fix": "DEBIAN-CVE-2026-55973",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-55973",
      "released": "2026-07-28T14:13:38Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "RHEL 10",
      "fixedVersion": "1.24.2-7.el10_2.4",
      "fix": "RHSA-2026:55892",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-55892",
      "released": "2026-08-18T23:09:46Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "RHEL 9",
      "fixedVersion": "0:1.24.2-3.el9_8.4",
      "fix": "RHSA-2026:55841",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-55841",
      "released": "2026-08-19T23:18:54Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "1.24.2-1ubuntu2.4",
      "fix": "unbound 1.24.2-1ubuntu2.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-unbound-1.24.2-1ubuntu2.4",
      "released": "2026-09-16T02:17:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "almalinux 10",
      "fixedVersion": "1.24.2-7.el10_2.4",
      "fix": "ALSA-2026:55892",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "almalinux 9",
      "fixedVersion": "1.24.2-3.el9_8.4",
      "fix": "ALSA-2026:55841",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55841",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "ol 10",
      "fixedVersion": "0:1.24.2-7.el10_2.4",
      "fix": "ELSA-2026-55892",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "ol 9",
      "fixedVersion": "0:1.24.2-3.el9_8.4",
      "fix": "ELSA-2026-55841",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55841",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "1.25.2-160000.1.1",
      "fix": "OPENSUSE-SU-2026:21550-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21550-1",
      "released": "2026-08-10T15:27:28Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "rocky 10",
      "fixedVersion": "0:1.24.2-7.el10_2.4",
      "fix": "RLSA-2026:55892",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2026-55892",
      "released": "2026-08-18T12:07:31Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "rocky 9",
      "fixedVersion": "0:1.24.2-3.el9_8.4",
      "fix": "RLSA-2026:55841",
      "url": "https://patchblox.com/security/fix/linux/rlsa-2026-55841",
      "released": "2026-08-18T06:04:25Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "sles 16.0",
      "fixedVersion": "1.25.2-160000.1.1",
      "fix": "SUSE-SU-2026:23226-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23226-1",
      "released": "2026-08-10T15:26:22Z"
    },
    {
      "platform": "linux",
      "product": "unbound-anchor",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "1.24.2-1ubuntu2.4",
      "fix": "unbound-anchor 1.24.2-1ubuntu2.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-unbound-anchor-1.24.2-1ubuntu2.4",
      "released": "2026-09-16T02:17:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-anchor",
      "release": "almalinux 10",
      "fixedVersion": "1.24.2-7.el10_2.4",
      "fix": "ALSA-2026:55892",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-anchor",
      "release": "ol 10",
      "fixedVersion": "0:1.24.2-7.el10_2.4",
      "fix": "ELSA-2026-55892",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-devel",
      "release": "RHEL 9",
      "fixedVersion": "0:1.24.2-3.el9_8.4",
      "fix": "RHSA-2026:55841",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-55841",
      "released": "2026-08-19T23:18:54Z"
    },
    {
      "platform": "linux",
      "product": "unbound-devel",
      "release": "almalinux 10",
      "fixedVersion": "1.24.2-7.el10_2.4",
      "fix": "ALSA-2026:55892",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-devel",
      "release": "almalinux 9",
      "fixedVersion": "1.24.2-3.el9_8.4",
      "fix": "ALSA-2026:55841",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55841",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-devel",
      "release": "ol 10",
      "fixedVersion": "0:1.24.2-7.el10_2.4",
      "fix": "ELSA-2026-55892",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-devel",
      "release": "ol 9",
      "fixedVersion": "0:1.24.2-3.el9_8.4",
      "fix": "ELSA-2026-55841",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55841",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-dracut",
      "release": "RHEL 9",
      "fixedVersion": "0:1.24.2-3.el9_8.4",
      "fix": "RHSA-2026:55841",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-55841",
      "released": "2026-08-19T23:18:54Z"
    },
    {
      "platform": "linux",
      "product": "unbound-dracut",
      "release": "almalinux 10",
      "fixedVersion": "1.24.2-7.el10_2.4",
      "fix": "ALSA-2026:55892",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
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    {
      "platform": "linux",
      "product": "unbound-dracut",
      "release": "almalinux 9",
      "fixedVersion": "1.24.2-3.el9_8.4",
      "fix": "ALSA-2026:55841",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55841",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-dracut",
      "release": "ol 10",
      "fixedVersion": "0:1.24.2-7.el10_2.4",
      "fix": "ELSA-2026-55892",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-dracut",
      "release": "ol 9",
      "fixedVersion": "0:1.24.2-3.el9_8.4",
      "fix": "ELSA-2026-55841",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55841",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-host",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "1.24.2-1ubuntu2.4",
      "fix": "unbound-host 1.24.2-1ubuntu2.4",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-unbound-host-1.24.2-1ubuntu2.4",
      "released": "2026-09-16T02:17:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-libs",
      "release": "RHEL 9",
      "fixedVersion": "0:1.24.2-3.el9_8.4",
      "fix": "RHSA-2026:55841",
      "url": "https://patchblox.com/security/fix/linux/rhsa-2026-55841",
      "released": "2026-08-19T23:18:54Z"
    },
    {
      "platform": "linux",
      "product": "unbound-libs",
      "release": "almalinux 10",
      "fixedVersion": "1.24.2-7.el10_2.4",
      "fix": "ALSA-2026:55892",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-libs",
      "release": "almalinux 9",
      "fixedVersion": "1.24.2-3.el9_8.4",
      "fix": "ALSA-2026:55841",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55841",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-libs",
      "release": "ol 10",
      "fixedVersion": "0:1.24.2-7.el10_2.4",
      "fix": "ELSA-2026-55892",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-libs",
      "release": "ol 9",
      "fixedVersion": "0:1.24.2-3.el9_8.4",
      "fix": "ELSA-2026-55841",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55841",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-utils",
      "release": "almalinux 10",
      "fixedVersion": "1.24.2-7.el10_2.4",
      "fix": "ALSA-2026:55892",
      "url": "https://patchblox.com/security/fix/linux/alsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-utils",
      "release": "ol 10",
      "fixedVersion": "0:1.24.2-7.el10_2.4",
      "fix": "ELSA-2026-55892",
      "url": "https://patchblox.com/security/fix/linux/elsa-2026-55892",
      "released": "2026-08-17T00:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}