{
  "document": {
    "aggregate_severity": {
      "text": "Medium"
    },
    "category": "csaf_vex",
    "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"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "https://tuxcare.com/contact/",
      "name": "TuxCare",
      "namespace": "https://tuxcare.com/"
    },
    "references": [
      {
        "category": "self",
        "summary": "Canonical URL",
        "url": "https://security.tuxcare.com/csaf/v2/els_os/centos-stream8els/vex/2026/cve-2026-4893-els_os-centos-stream8els.json"
      }
    ],
    "tracking": {
      "current_release_date": "2026-05-22T08:14:17Z",
      "generator": {
        "date": "2026-05-22T08:14:17Z",
        "engine": {
          "name": "pyCSAF"
        }
      },
      "id": "CVE-2026-4893-ELS_OS-CENTOS-STREAM8ELS",
      "initial_release_date": "2026-05-09T00:00:00Z",
      "revision_history": [
        {
          "date": "2026-05-09T00:00:00Z",
          "number": "1",
          "summary": "Initial version"
        },
        {
          "date": "2026-05-22T08:14:17Z",
          "number": "2",
          "summary": "Official Publication"
        }
      ],
      "status": "final",
      "version": "2"
    },
    "title": "Security update on CVE-2026-4893"
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_name",
                "name": "Community Enterprise Operating System 8",
                "product": {
                  "name": "Community Enterprise Operating System 8",
                  "product_id": "CentOS-Stream-8",
                  "product_identification_helper": {
                    "cpe": "cpe:2.3:o:centos:centos:8:*:*:*:*:*:*:*"
                  }
                }
              }
            ],
            "category": "product_family",
            "name": "Community Enterprise Operating System"
          },
          {
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              {
                "category": "product_version",
                "name": "dnsmasq-utils-0:2.79-33.el8.x86_64",
                "product": {
                  "name": "dnsmasq-utils-0:2.79-33.el8.x86_64",
                  "product_id": "dnsmasq-utils-0:2.79-33.el8.x86_64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/centos/dnsmasq-utils@2.79-33.el8?arch=x86_64"
                  }
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              },
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                "name": "dnsmasq-0:2.79-33.el8.x86_64",
                "product": {
                  "name": "dnsmasq-0:2.79-33.el8.x86_64",
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                  "product_identification_helper": {
                    "purl": "pkg:rpm/centos/dnsmasq@2.79-33.el8?arch=x86_64"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "x86_64"
          }
        ],
        "category": "vendor",
        "name": "Red Hat, Inc."
      },
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "dnsmasq-utils-0:2.79-33.el8.tuxcare.els1.x86_64",
                "product": {
                  "name": "dnsmasq-utils-0:2.79-33.el8.tuxcare.els1.x86_64",
                  "product_id": "dnsmasq-utils-0:2.79-33.el8.tuxcare.els1.x86_64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/tuxcare/dnsmasq-utils@2.79-33.el8.tuxcare.els1?arch=x86_64"
                  }
                }
              },
              {
                "category": "product_version",
                "name": "dnsmasq-0:2.79-33.el8.tuxcare.els1.x86_64",
                "product": {
                  "name": "dnsmasq-0:2.79-33.el8.tuxcare.els1.x86_64",
                  "product_id": "dnsmasq-0:2.79-33.el8.tuxcare.els1.x86_64",
                  "product_identification_helper": {
                    "purl": "pkg:rpm/tuxcare/dnsmasq@2.79-33.el8.tuxcare.els1?arch=x86_64"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "x86_64"
          }
        ],
        "category": "vendor",
        "name": "TuxCare"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "dnsmasq-utils-0:2.79-33.el8.tuxcare.els1.x86_64 as a component of Community Enterprise Operating System 8",
          "product_id": "CentOS-Stream-8:dnsmasq-utils-0:2.79-33.el8.tuxcare.els1.x86_64"
        },
        "product_reference": "dnsmasq-utils-0:2.79-33.el8.tuxcare.els1.x86_64",
        "relates_to_product_reference": "CentOS-Stream-8"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "dnsmasq-0:2.79-33.el8.tuxcare.els1.x86_64 as a component of Community Enterprise Operating System 8",
          "product_id": "CentOS-Stream-8:dnsmasq-0:2.79-33.el8.tuxcare.els1.x86_64"
        },
        "product_reference": "dnsmasq-0:2.79-33.el8.tuxcare.els1.x86_64",
        "relates_to_product_reference": "CentOS-Stream-8"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "dnsmasq-utils-0:2.79-33.el8.x86_64 as a component of Community Enterprise Operating System 8",
          "product_id": "CentOS-Stream-8:dnsmasq-utils-0:2.79-33.el8.x86_64"
        },
        "product_reference": "dnsmasq-utils-0:2.79-33.el8.x86_64",
        "relates_to_product_reference": "CentOS-Stream-8"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "dnsmasq-0:2.79-33.el8.x86_64 as a component of Community Enterprise Operating System 8",
          "product_id": "CentOS-Stream-8:dnsmasq-0:2.79-33.el8.x86_64"
        },
        "product_reference": "dnsmasq-0:2.79-33.el8.x86_64",
        "relates_to_product_reference": "CentOS-Stream-8"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-4893",
      "cwe": {
        "id": "CWE-20",
        "name": "Improper Input Validation"
      },
      "notes": [
        {
          "category": "description",
          "text": "A validation bypass was discovered in dnsmasq's RFC 7871 client subnet (ECS) handling. When verifying ECS source information in DNS responses, dnsmasq passes the OPT record length instead of the full packet length to the validation function.This causes all internal bounds checks to fail, completely bypassing ECS source validation and allowing an attacker to spoof client subnet information.",
          "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": [
          "CentOS-Stream-8:dnsmasq-0:2.79-33.el8.tuxcare.els1.x86_64",
          "CentOS-Stream-8:dnsmasq-utils-0:2.79-33.el8.tuxcare.els1.x86_64"
        ],
        "known_affected": [
          "CentOS-Stream-8:dnsmasq-0:2.79-33.el8.x86_64",
          "CentOS-Stream-8:dnsmasq-utils-0:2.79-33.el8.x86_64"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://cve.tuxcare.com/els/cve/CVE-2026-4893"
        }
      ],
      "release_date": "2026-05-09T00:00:00Z",
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-05-22T08:13:31.445856Z",
          "details": "Details on how to apply the fix are available at: https://cve.tuxcare.com/els/releases/CLSA-2026:1779437608",
          "product_ids": [
            "CentOS-Stream-8:dnsmasq-0:2.79-33.el8.tuxcare.els1.x86_64",
            "CentOS-Stream-8:dnsmasq-utils-0:2.79-33.el8.tuxcare.els1.x86_64"
          ],
          "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1779437608"
        },
        {
          "category": "none_available",
          "date": "2026-05-09T00:00:00Z",
          "details": "Affected",
          "product_ids": [
            "CentOS-Stream-8:dnsmasq-0:2.79-33.el8.x86_64",
            "CentOS-Stream-8:dnsmasq-utils-0:2.79-33.el8.x86_64"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
            "version": "3.1"
          },
          "products": [
            "CentOS-Stream-8:dnsmasq-0:2.79-33.el8.tuxcare.els1.x86_64",
            "CentOS-Stream-8:dnsmasq-0:2.79-33.el8.x86_64",
            "CentOS-Stream-8:dnsmasq-utils-0:2.79-33.el8.tuxcare.els1.x86_64",
            "CentOS-Stream-8:dnsmasq-utils-0:2.79-33.el8.x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Moderate"
        }
      ]
    }
  ]
}