{
  "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": "CVE-2026-4890: fix NSEC bitmap parsing infinite loop in DNSSEC validation\n- CVE-2026-4891: verify rdlen field in RRSIG packets\n- CVE-2026-4892: fix buffer overflow in helper.c with large DHCPv6 CLIDs",
        "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-2026:1779273053",
        "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1779273053"
      },
      {
        "category": "self",
        "summary": "Canonical URL",
        "url": "https://security.tuxcare.com/csaf/v2/els_os/amazonlinux2els/advisories/2026/clsa-2026_1779273053.json"
      }
    ],
    "tracking": {
      "current_release_date": "2026-05-20T10:31:39Z",
      "generator": {
        "date": "2026-05-20T10:31:39Z",
        "engine": {
          "name": "pyCSAF"
        }
      },
      "id": "CLSA-2026:1779273053",
      "initial_release_date": "2026-05-20T10:31:39Z",
      "revision_history": [
        {
          "date": "2026-05-20T10:31:39Z",
          "number": "1",
          "summary": "Initial version"
        }
      ],
      "status": "final",
      "version": "1"
    },
    "title": "dnsmasq: Fix of 3 CVEs"
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_name",
                "name": "Amazon Linux 2",
                "product": {
                  "name": "Amazon Linux 2",
                  "product_id": "Amazon-Linux-2",
                  "product_identification_helper": {
                    "cpe": "cpe:2.3:o:amazon:amazon_linux:2:*:*:*:*:*:*:*"
                  }
                }
              }
            ],
            "category": "product_family",
            "name": "Amazon Linux"
          }
        ],
        "category": "vendor",
        "name": "Amazon Web Services, Inc."
      },
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
                "product": {
                  "name": "dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
                  "product_id": "dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/tuxcare/dnsmasq-utils@2.76-17.amzn2.1.5.3.tuxcare.els4?arch=x86_64"
                  }
                }
              },
              {
                "category": "product_version",
                "name": "dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
                "product": {
                  "name": "dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
                  "product_id": "dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/tuxcare/dnsmasq@2.76-17.amzn2.1.5.3.tuxcare.els4?arch=x86_64"
                  }
                }
              },
              {
                "category": "product_version",
                "name": "dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
                "product": {
                  "name": "dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
                  "product_id": "dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/tuxcare/dnsmasq-utils@2.76-17.amzn2.1.5.3.tuxcare.els3?arch=x86_64"
                  }
                }
              },
              {
                "category": "product_version",
                "name": "dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
                "product": {
                  "name": "dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
                  "product_id": "dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/tuxcare/dnsmasq@2.76-17.amzn2.1.5.3.tuxcare.els3?arch=x86_64"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "x86_64"
          }
        ],
        "category": "vendor",
        "name": "TuxCare"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64 as a component of Amazon Linux 2",
          "product_id": "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64"
        },
        "product_reference": "dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
        "relates_to_product_reference": "Amazon-Linux-2"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64 as a component of Amazon Linux 2",
          "product_id": "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64"
        },
        "product_reference": "dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
        "relates_to_product_reference": "Amazon-Linux-2"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64 as a component of Amazon Linux 2",
          "product_id": "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64"
        },
        "product_reference": "dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
        "relates_to_product_reference": "Amazon-Linux-2"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64 as a component of Amazon Linux 2",
          "product_id": "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64"
        },
        "product_reference": "dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
        "relates_to_product_reference": "Amazon-Linux-2"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-4891",
      "cwe": {
        "id": "CWE-125",
        "name": "Out-of-bounds Read"
      },
      "notes": [
        {
          "category": "description",
          "text": "A heap out-of-bounds read vulnerability was discovered in dnsmasq's DNSSEC validation. When processing RRSIG records, dnsmasq calculates the signature length by subtracting the fixed field size from the record's declared data length. A crafted RRSIG record with a data length smaller than the fixed fields causes this calculation to underflow, potentially resulting in an out-of-bounds read and process crash.",
          "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": [
          "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
          "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64"
        ],
        "known_affected": [
          "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
          "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://cve.tuxcare.com/els/cve/CVE-2026-4891"
        }
      ],
      "release_date": "2026-05-09T00:00:00Z",
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-05-20T10:30:55.735136Z",
          "details": "Details on how to apply the fix are available at: https://cve.tuxcare.com/els/releases/CLSA-2026:1779273053",
          "product_ids": [
            "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
            "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64"
          ],
          "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1779273053"
        },
        {
          "category": "none_available",
          "date": "2026-05-09T00:00:00Z",
          "details": "Affected",
          "product_ids": [
            "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
            "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64"
          ]
        }
      ],
      "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": [
            "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
            "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Important"
        }
      ]
    },
    {
      "cve": "CVE-2026-4892",
      "cwe": {
        "id": "CWE-122",
        "name": "Heap-based Buffer Overflow"
      },
      "notes": [
        {
          "category": "description",
          "text": "A heap buffer overflow was discovered in dnsmasq's DHCP script helper process. When processing DHCPv6 client identifiers (CLIDs), the helper hex-encodes the raw CLID bytes into a fixed-size buffer without length validation. Since DHCPv6 CLIDs can be up to 65,535 bytes, a crafted DHCPv6 packet can overflow the buffer with attacker-controlled content. The helper process runs with root privileges.",
          "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": [
          "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
          "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64"
        ],
        "known_affected": [
          "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
          "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://cve.tuxcare.com/els/cve/CVE-2026-4892"
        }
      ],
      "release_date": "2026-05-09T00:00:00Z",
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-05-20T10:30:55.735136Z",
          "details": "Details on how to apply the fix are available at: https://cve.tuxcare.com/els/releases/CLSA-2026:1779273053",
          "product_ids": [
            "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
            "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64"
          ],
          "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1779273053"
        },
        {
          "category": "none_available",
          "date": "2026-05-09T00:00:00Z",
          "details": "Affected",
          "product_ids": [
            "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
            "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "ADJACENT_NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "products": [
            "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
            "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Important"
        }
      ]
    },
    {
      "cve": "CVE-2026-4890",
      "cwe": {
        "id": "CWE-835",
        "name": "Loop with Unreachable Exit Condition ('Infinite Loop')"
      },
      "notes": [
        {
          "category": "description",
          "text": "A denial of service vulnerability was discovered in dnsmasq's DNSSEC validation. When parsing NSEC and NSEC3 bitmap records, the window iteration logic fails to account for the 2-byte window header when advancing through the bitmap data. A specially crafted DNS response with a zero-length bitmap can cause an infinite loop, making dnsmasq unresponsive to all queries.",
          "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": [
          "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
          "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64"
        ],
        "known_affected": [
          "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
          "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://cve.tuxcare.com/els/cve/CVE-2026-4890"
        }
      ],
      "release_date": "2026-05-09T00:00:00Z",
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-05-20T10:30:55.735136Z",
          "details": "Details on how to apply the fix are available at: https://cve.tuxcare.com/els/releases/CLSA-2026:1779273053",
          "product_ids": [
            "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
            "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64"
          ],
          "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1779273053"
        },
        {
          "category": "none_available",
          "date": "2026-05-09T00:00:00Z",
          "details": "Affected",
          "product_ids": [
            "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64",
            "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els3.x86_64"
          ]
        }
      ],
      "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": [
            "Amazon-Linux-2:dnsmasq-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64",
            "Amazon-Linux-2:dnsmasq-utils-0:2.76-17.amzn2.1.5.3.tuxcare.els4.x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Important"
        }
      ]
    }
  ]
}