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Critical

Security advisory

Type: advisorySources: OSVCVE: CVE-2026-3593

A use-after-free vulnerability exists within the DNS-over-HTTPS implementation. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.0 through 9.18.48 and 9.18.11-S1 through 9.18.48-S1 are NOT affected.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-3593
Confirmed fixed CVEs
Not specified
Updated in this feed
1 Nov 2026, 07:01 UTC · Revision 1

Source evidence

CVE-2026-3593

core-osv · Original source

Published 20 May 2026, 13:16 UTC

A use-after-free vulnerability exists within the DNS-over-HTTPS implementation. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.0 through 9.18.48 and 9.18.11-S1 through 9.18.48-S1 are NOT affected.

osv:CVE-2026-3593
Complete source record
{
  "id": "fd0051e573badcaf77c00dcca98743021930cb238138b35367b4e83d3a30942c",
  "url": "https://osv.dev/vulnerability/CVE-2026-3593",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2026-3593",
    "summary": "A use-after-free vulnerability exists within the DNS-over-HTTPS implementation. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.0 through 9.18.48 and 9.18.11-S1 through 9.18.48-S1 are NOT affected.",
    "evidence": "osv:CVE-2026-3593",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-3593",
      "aliases": [
        "CVE-2026-3593"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/isc-projects/bind9",
              "type": "GIT",
              "events": [
                {
                  "introduced": "14bbdfc7b9db0870a0b8941ca8812d9983fdba1a"
                },
                {
                  "fixed": "7d0b4d4d436e7b950225a533e5bc56d8f935cc1c"
                },
                {
                  "introduced": "b732da695eecc0526950e2c722cde0bf23e5a070"
                },
                {
                  "fixed": "02a7b2c8a549b79cf885d1a0cda28b74de22d197"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
                    "range": [
                      {
                        "introduced": "9.20.0"
                      },
                      {
                        "fixed": "9.20.23"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
                    "range": [
                      {
                        "introduced": "9.21.0"
                      },
                      {
                        "fixed": "9.21.22"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-3593.json"
          }
        },
        {
          "ranges": [
            {
              "repo": "https://gitlab.isc.org/isc-projects/bind9",
              "type": "GIT",
              "events": [
                {
                  "introduced": "14bbdfc7b9db0870a0b8941ca8812d9983fdba1a"
                },
                {
                  "fixed": "7d0b4d4d436e7b950225a533e5bc56d8f935cc1c"
                },
                {
                  "introduced": "b732da695eecc0526950e2c722cde0bf23e5a070"
                },
                {
                  "fixed": "02a7b2c8a549b79cf885d1a0cda28b74de22d197"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
                    "range": [
                      {
                        "introduced": "9.20.0"
                      },
                      {
                        "fixed": "9.20.23"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
                    "range": [
                      {
                        "introduced": "9.21.0"
                      },
                      {
                        "fixed": "9.21.22"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-3593.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:47.521218394Z",
      "provider": "osv",
      "references": [
        "https://access.redhat.com/security/cve/CVE-2026-3593",
        "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3593.json",
        "https://access.redhat.com/errata/RHSA-2026:7412",
        "https://kb.isc.org/docs/cve-2026-3593",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2479770",
        "https://downloads.isc.org/isc/bind9/9.20.23",
        "https://downloads.isc.org/isc/bind9/9.21.22"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2026-3593",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 436569,
  "published_at": "2026-05-20T13:16:23.923+00:00"
}