{ "document": { "aggregate_severity": { "text": "Important" }, "category": "csaf_security_advisory", "csaf_version": "2.0", "distribution": { "text": "TuxCare License Agreement", "tlp": { "label": "WHITE", "url": "https://www.first.org/tlp/" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Cloud Linux Inc. and provide a link to the original.", "title": "Terms of Use" }, { "category": "details", "text": "* SECURITY UPDATE: Multiple assertion failures in named when handling DNS\n messages with non-IN class (CHAOS, HESIOD) or meta-classes (ANY, NONE)\n in UPDATE, NOTIFY, and recursion paths\n - debian/patches/CVE-2026-5946.patch: disable recursion for non-IN views,\n reject UPDATE and NOTIFY for non-IN classes, validate DNS message CLASS\n early in request processing, reject NONE/ANY meta-classes in UPDATE and\n NOTIFY questions, and skip deny-answer-address for non-IN addresses in\n bin/named/server.c, lib/bind9/check.c, lib/dns/adb.c,\n lib/dns/message.c, lib/dns/resolver.c, lib/ns/client.c, lib/ns/update.c\n - CVE-2026-5946", "title": "Details" } ], "publisher": { "category": "vendor", "contact_details": "https://tuxcare.com/contact/", "name": "TuxCare", "namespace": "https://tuxcare.com/" }, "references": [ { "category": "self", "summary": "https://cve.tuxcare.com/els/releases/CLSA-2026:1780406874", "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1780406874" }, { "category": "self", "summary": "Canonical URL", "url": "https://security.tuxcare.com/csaf/v2/els_os/ubuntu20.04els/advisories/2026/clsa-2026_1780406874.json" } ], "tracking": { "current_release_date": "2026-06-02T17:34:18Z", "generator": { "date": "2026-06-02T17:34:18Z", "engine": { "name": "pyCSAF" } }, "id": "CLSA-2026:1780406874", "initial_release_date": "2026-06-02T13:27:57Z", "revision_history": [ { "date": "2026-06-02T13:27:57Z", "number": "1", "summary": "Initial version" }, { "date": "2026-06-02T17:34:18Z", "number": "2", "summary": "Official Publication" } ], "status": "final", "version": "2" }, "title": "Fix CVE(s): CVE-2026-3039, CVE-2026-5946" }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_name", "name": "Ubuntu 20.04", "product": { "name": "Ubuntu 20.04", "product_id": "Ubuntu-20", "product_identification_helper": { "cpe": "cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*" } } } ], "category": "product_family", "name": "Ubuntu" } ], "category": "vendor", "name": "Canonical Ltd." }, { "branches": [ { "branches": [ { "category": "product_version", "name": "bind9-doc-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "product": { "name": "bind9-doc-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "product_id": "bind9-doc-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "product_identification_helper": { "purl": "pkg:deb/tuxcare/bind9-doc@1:9.18.30-0ubuntu0.20.04.2%2Btuxcare.els2?arch=all" } } }, { "category": "product_version", "name": "bind9utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "product": { "name": "bind9utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "product_id": "bind9utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "product_identification_helper": { "purl": "pkg:deb/tuxcare/bind9utils@1:9.18.30-0ubuntu0.20.04.2%2Btuxcare.els2?arch=all" } } }, { "category": "product_version", "name": "dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "product": { "name": "dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "product_id": "dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "product_identification_helper": { "purl": "pkg:deb/tuxcare/dnsutils@1:9.18.30-0ubuntu0.20.04.2%2Btuxcare.els2?arch=all" } } } ], "category": "architecture", "name": "all" }, { "branches": [ { "category": "product_version", "name": "bind9-host-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product": { "name": "bind9-host-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product_id": "bind9-host-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product_identification_helper": { "purl": "pkg:deb/tuxcare/bind9-host@1:9.18.30-0ubuntu0.20.04.2%2Btuxcare.els2?arch=amd64" } } }, { "category": "product_version", "name": "bind9-libs-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product": { "name": "bind9-libs-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product_id": "bind9-libs-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product_identification_helper": { "purl": "pkg:deb/tuxcare/bind9-libs@1:9.18.30-0ubuntu0.20.04.2%2Btuxcare.els2?arch=amd64" } } }, { "category": "product_version", "name": "bind9-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product": { "name": "bind9-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product_id": "bind9-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product_identification_helper": { "purl": "pkg:deb/tuxcare/bind9@1:9.18.30-0ubuntu0.20.04.2%2Btuxcare.els2?arch=amd64" } } }, { "category": "product_version", "name": "bind9-dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product": { "name": "bind9-dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product_id": "bind9-dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product_identification_helper": { "purl": "pkg:deb/tuxcare/bind9-dnsutils@1:9.18.30-0ubuntu0.20.04.2%2Btuxcare.els2?arch=amd64" } } }, { "category": "product_version", "name": "bind9-utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product": { "name": "bind9-utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product_id": "bind9-utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "product_identification_helper": { "purl": "pkg:deb/tuxcare/bind9-utils@1:9.18.30-0ubuntu0.20.04.2%2Btuxcare.els2?arch=amd64" } } } ], "category": "architecture", "name": "amd64" } ], "category": "vendor", "name": "TuxCare" } ], "relationships": [ { "category": "default_component_of", "full_product_name": { "name": "bind9-doc-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all as a component of Ubuntu 20.04", "product_id": "Ubuntu-20:bind9-doc-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all" }, "product_reference": "bind9-doc-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "relates_to_product_reference": "Ubuntu-20" }, { "category": "default_component_of", "full_product_name": { "name": "bind9-host-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64 as a component of Ubuntu 20.04", "product_id": "Ubuntu-20:bind9-host-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64" }, "product_reference": "bind9-host-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "relates_to_product_reference": "Ubuntu-20" }, { "category": "default_component_of", "full_product_name": { "name": "bind9utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all as a component of Ubuntu 20.04", "product_id": "Ubuntu-20:bind9utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all" }, "product_reference": "bind9utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "relates_to_product_reference": "Ubuntu-20" }, { "category": "default_component_of", "full_product_name": { "name": "bind9-libs-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64 as a component of Ubuntu 20.04", "product_id": "Ubuntu-20:bind9-libs-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64" }, "product_reference": "bind9-libs-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "relates_to_product_reference": "Ubuntu-20" }, { "category": "default_component_of", "full_product_name": { "name": "bind9-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64 as a component of Ubuntu 20.04", "product_id": "Ubuntu-20:bind9-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64" }, "product_reference": "bind9-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "relates_to_product_reference": "Ubuntu-20" }, { "category": "default_component_of", "full_product_name": { "name": "bind9-dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64 as a component of Ubuntu 20.04", "product_id": "Ubuntu-20:bind9-dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64" }, "product_reference": "bind9-dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "relates_to_product_reference": "Ubuntu-20" }, { "category": "default_component_of", "full_product_name": { "name": "dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all as a component of Ubuntu 20.04", "product_id": "Ubuntu-20:dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all" }, "product_reference": "dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "relates_to_product_reference": "Ubuntu-20" }, { "category": "default_component_of", "full_product_name": { "name": "bind9-utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64 as a component of Ubuntu 20.04", "product_id": "Ubuntu-20:bind9-utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64" }, "product_reference": "bind9-utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "relates_to_product_reference": "Ubuntu-20" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-3039", "cwe": { "id": "CWE-771", "name": "Missing Reference to Active Allocated Resource" }, "notes": [ { "category": "description", "text": "BIND servers that are configured to use TKEY-based authentication via GSS-API tokens are vulnerable to excessive memory consumption when receiving and processing maliciously-constructed packets. Typically these servers will be found in Active Directory integrated DNS deployments and/or Kerberos-secured DNS environments.\nThis issue affects BIND 9 versions 9.0.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.9.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.", "title": "Vulnerability description" }, { "category": "general", "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.", "title": "CVSS score applicability" } ], "product_status": { "fixed": [ "Ubuntu-20:bind9-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-doc-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "Ubuntu-20:bind9-host-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-libs-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "Ubuntu-20:dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all" ] }, "references": [ { "category": "self", "summary": "Canonical URL", "url": "https://cve.tuxcare.com/els/cve/CVE-2026-3039" }, { "category": "external", "summary": "https://downloads.isc.org/isc/bind9/9.18.49", "url": "https://downloads.isc.org/isc/bind9/9.18.49" }, { "category": "external", "summary": "https://downloads.isc.org/isc/bind9/9.20.23", "url": "https://downloads.isc.org/isc/bind9/9.20.23" }, { "category": "external", "summary": "https://downloads.isc.org/isc/bind9/9.21.22", "url": "https://downloads.isc.org/isc/bind9/9.21.22" }, { "category": "external", "summary": "https://kb.isc.org/docs/cve-2026-3039", "url": "https://kb.isc.org/docs/cve-2026-3039" } ], "release_date": "2026-05-20T13:16:00Z", "remediations": [ { "category": "vendor_fix", "date": "2026-06-02T13:27:57.875929Z", "details": "Details on how to apply the fix are available at: https://cve.tuxcare.com/els/releases/CLSA-2026:1780406874", "product_ids": [ "Ubuntu-20:bind9-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-doc-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "Ubuntu-20:bind9-host-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-libs-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "Ubuntu-20:dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all" ], "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1780406874" } ], "scores": [ { "cvss_v3": { "attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1" }, "products": [ "Ubuntu-20:bind9-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-doc-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "Ubuntu-20:bind9-host-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-libs-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "Ubuntu-20:dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all" ] } ], "threats": [ { "category": "impact", "details": "Important" } ] }, { "cve": "CVE-2026-5946", "cwe": { "id": "CWE-20", "name": "Improper Input Validation" }, "notes": [ { "category": "description", "text": "Multiple flaws have been identified in `named` related to the handling of DNS messages whose CLASS is not Internet (`IN`) — for example, `CHAOS` or `HESIOD`, or DNS messages that specify meta-classes (`ANY` or `NONE`) in the question section. Specially crafted requests reaching the affected code paths — recursion, dynamic updates (`UPDATE`), zone change notifications (`NOTIFY`), or processing of `IN`-specific record types in non-`IN` data — can cause assertion failures in `named`.\nThis issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.", "title": "Vulnerability description" }, { "category": "general", "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.", "title": "CVSS score applicability" } ], "product_status": { "fixed": [ "Ubuntu-20:bind9-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-doc-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "Ubuntu-20:bind9-host-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-libs-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "Ubuntu-20:dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all" ] }, "references": [ { "category": "self", "summary": "Canonical URL", "url": "https://cve.tuxcare.com/els/cve/CVE-2026-5946" }, { "category": "external", "summary": "https://downloads.isc.org/isc/bind9/9.18.49", "url": "https://downloads.isc.org/isc/bind9/9.18.49" }, { "category": "external", "summary": "https://downloads.isc.org/isc/bind9/9.20.23", "url": "https://downloads.isc.org/isc/bind9/9.20.23" }, { "category": "external", "summary": "https://downloads.isc.org/isc/bind9/9.21.22", "url": "https://downloads.isc.org/isc/bind9/9.21.22" }, { "category": "external", "summary": "https://kb.isc.org/docs/cve-2026-5946", "url": "https://kb.isc.org/docs/cve-2026-5946" } ], "release_date": "2026-05-20T13:16:00Z", "remediations": [ { "category": "vendor_fix", "date": "2026-06-02T13:27:57.875929Z", "details": "Details on how to apply the fix are available at: https://cve.tuxcare.com/els/releases/CLSA-2026:1780406874", "product_ids": [ "Ubuntu-20:bind9-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-doc-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "Ubuntu-20:bind9-host-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-libs-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "Ubuntu-20:dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all" ], "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1780406874" } ], "scores": [ { "cvss_v3": { "attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1" }, "products": [ "Ubuntu-20:bind9-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-doc-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "Ubuntu-20:bind9-host-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-libs-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9-utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.amd64", "Ubuntu-20:bind9utils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all", "Ubuntu-20:dnsutils-1:9.18.30-0ubuntu0.20.04.2+tuxcare.els2.all" ] } ], "threats": [ { "category": "impact", "details": "Important" } ] } ] }