{
  "cveId": "CVE-2026-82720",
  "url": "https://patchblox.com/security/cve/CVE-2026-82720",
  "summary": "CVE-2026-82720 is fixed in 12 products on 1 platform, first by DEBIAN-CVE-2026-82720, released September 19, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "Use-after-free in DoH stream cleanup code path",
  "description": "NLnet Labs Unbound 1.12.0 up to and including 1.26.0 has a use-after-free vulnerability when compiled for DNS-over-HTTPs support with \u0027--with-libnghttp2\u0027. During failure code paths (i.e., RPZ drop query, jostle due to heavy traffic), a dropped DoH stream brings down the whole DoH session and does not account properly for other DoH streams in the same session. This leads to use-after-free in those code paths. If the prerequisites are satisfied (possible RPZ drop or heavy client traffic), a malicious actor can trigger the vulnerability with a single DoH connection and the appropriate traffic. Impact is limited as the reads are not user controlled and the use-after-free leads to early returns. However, a hardened allocator can catch the use-after-free and controllably terminate the process resulting to denial of service.",
  "published": "2026-09-16T09:17:06Z",
  "severity": "Moderate",
  "cvss": 5.9,
  "cvssVector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
  "cwe": "Use After Free",
  "epss": 0.00382,
  "epssPercentile": 0.32614,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-82720",
  "fixes": [
    {
      "platform": "linux",
      "product": "python3-unbound",
      "release": "amzn 2023",
      "fixedVersion": "1.17.1-1.amzn2023.0.15",
      "fix": "ALAS2023-2026-3127",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3127",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "python3-unbound-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1.17.1-1.amzn2023.0.15",
      "fix": "ALAS2023-2026-3127",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3127",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "1.26.1-0\u002Bdeb13u1",
      "fix": "DEBIAN-CVE-2026-82720",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-82720",
      "released": "2026-09-19T18:30:58Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "Debian 14",
      "fixedVersion": "1.26.1-1",
      "fix": "DEBIAN-CVE-2026-82720",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-82720",
      "released": "2026-09-19T18:30:58Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "amzn 2023",
      "fixedVersion": "1.17.1-1.amzn2023.0.15",
      "fix": "ALAS2023-2026-3127",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3127",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "1.26.1-160000.1.1",
      "fix": "OPENSUSE-SU-2026:22082-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-22082-1",
      "released": "2026-11-07T00:48:28Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "sles 15.6",
      "fixedVersion": "1.26.1-150600.23.24.1",
      "fix": "SUSE-SU-2026:4620-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4620-1",
      "released": "2026-11-07T00:43:02Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "sles 15.7",
      "fixedVersion": "1.26.1-150600.23.24.1",
      "fix": "SUSE-SU-2026:4620-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-4620-1",
      "released": "2026-11-07T00:43:02Z"
    },
    {
      "platform": "linux",
      "product": "unbound",
      "release": "sles 16.0",
      "fixedVersion": "1.26.1-160000.1.1",
      "fix": "SUSE-SU-2026:24226-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-24226-1",
      "released": "2026-11-07T00:45:20Z"
    },
    {
      "platform": "linux",
      "product": "unbound-anchor",
      "release": "amzn 2023",
      "fixedVersion": "1.17.1-1.amzn2023.0.15",
      "fix": "ALAS2023-2026-3127",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3127",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-anchor-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1.17.1-1.amzn2023.0.15",
      "fix": "ALAS2023-2026-3127",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3127",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1.17.1-1.amzn2023.0.15",
      "fix": "ALAS2023-2026-3127",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3127",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-debugsource",
      "release": "amzn 2023",
      "fixedVersion": "1.17.1-1.amzn2023.0.15",
      "fix": "ALAS2023-2026-3127",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3127",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-devel",
      "release": "amzn 2023",
      "fixedVersion": "1.17.1-1.amzn2023.0.15",
      "fix": "ALAS2023-2026-3127",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3127",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-libs",
      "release": "amzn 2023",
      "fixedVersion": "1.17.1-1.amzn2023.0.15",
      "fix": "ALAS2023-2026-3127",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3127",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-libs-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1.17.1-1.amzn2023.0.15",
      "fix": "ALAS2023-2026-3127",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3127",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-utils",
      "release": "amzn 2023",
      "fixedVersion": "1.17.1-1.amzn2023.0.15",
      "fix": "ALAS2023-2026-3127",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3127",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "unbound-utils-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1.17.1-1.amzn2023.0.15",
      "fix": "ALAS2023-2026-3127",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3127",
      "released": "2026-09-28T09:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-10T20:03:11Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}