CVE-2026-43964

Estado: ModificadaAlta (7.5)—

Postfix before 3.8.16, 3.9 before 3.9.10, and 3.10 before 3.10.9 sometimes allows a buffer over-read and process crash via an enhanced status code that lacks text after the third number.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Puntuación base: 7.5

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.88%
Percentil entre todas las CVEs puntuadas: 58
Fecha de la puntuación: 5/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access85 %
Impacto principalT1499.004 Application or System Exploitationimpact80 %

Postfix remoto sin autenticación permite crash por buffer over-read en código de estado mejorado; DoS en servidor SMTP accesible en red.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Filter Network Traffic Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Application Isolation and Sandboxing

Tecnologías afectadas (1)

Postfix — Postfix

CWE

CWE-193
CWE-193

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-43964",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-43964",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-05-04T19:49:30.949584Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "cve@mitre.org",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 3.7,
          "attackVector": "NETWORK",
          "baseSeverity": "LOW",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "LOW",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 1.4,
        "exploitabilityScore": 2.2
      },
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      },
      {
        "type": "Secondary",
        "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "Postfix",
          "product": "Postfix",
          "versions": [
            {
              "status": "affected",
              "version": "2.3",
              "lessThan": "3.8.16",
              "versionType": "custom"
            },
            {
              "status": "affected",
              "version": "3.9",
              "lessThan": "3.9.10",
              "versionType": "custom"
            },
            {
              "status": "affected",
              "version": "3.10",
              "lessThan": "3.10.9",
              "versionType": "custom"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ]
    },
    {
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "affectedData": [
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:10.2"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 10",
          "versions": [
            {
              "status": "unaffected",
              "version": "2:3.8.5-10.el10_2",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "postfix",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux_eus:10.0"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 10.0 Extended Update Support",
          "versions": [
            {
              "status": "unaffected",
              "version": "2:3.8.5-8.el10_0.1",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "postfix",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:rhel_els:7"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 7 Extended Lifecycle Support",
          "versions": [
            {
              "status": "unaffected",
              "version": "2:2.10.1-9.el7_9.1",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "postfix",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:enterprise_linux:8",
            "cpe:/o:redhat:enterprise_linux:8"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8",
          "versions": [
            {
              "status": "unaffected",
              "version": "2:3.5.8-8.el8_10",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "postfix",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhel_aus:8.4"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support",
          "versions": [
            {
              "status": "unaffected",
              "version": "2:3.5.8-1.el8_4.1",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "postfix",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhel_eus_long_life:8.4"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On",
          "versions": [
            {
              "status": "unaffected",
              "version": "2:3.5.8-1.el8_4.1",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "postfix",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhel_aus:8.6"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support",
          "versions": [
            {
              "status": "unaffected",
              "version": "2:3.5.8-4.el8_6.1",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "postfix",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhel_eus_long_life:8.6"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On",
          "versions": [
            {
              "status": "unaffected",
              "version": "2:3.5.8-4.el8_6.1",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "postfix",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhel_tus:8.8"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8.8 Telecommunications Update Service",
          "versions": [
            {
              "status": "unaffected",
              "version": "2:3.5.8-4.el8_8.1",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "postfix",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:rhel_e4s:8.8"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions",
          "versions": [
            {
              "status": "unaffected",
              "version": "2:3.5.8-4.el8_8.1",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "postfix",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/a:redhat:enterprise_linux:9"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 9",
          "versions": [
            {
              "status": "unaffected",
              "version": "2:3.5.25-3.el9_8",
              "lessThan": "*",
              "versionType": "rpm"
            }
          ],
          "packageName": "postfix",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "affected"
        },
        {
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:6"
          ],
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 6",
          "packageName": "postfix",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "defaultStatus": "unknown"
        }
      ]
    }
  ],
  "published": "2026-05-04T19:16:07.143",
  "references": [
    {
      "url": "https://www.mail-archive.com/postfix-announce@postfix.org/msg00110.html",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "http://www.openwall.com/lists/oss-security/2026/05/04/30",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:25930",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:25932",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:26205",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:50963",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:50964",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:51034",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:51436",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:57174",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://access.redhat.com/security/cve/CVE-2026-43964",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2466488",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    },
    {
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43964.json",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "cve@mitre.org",
      "description": [
        {
          "lang": "en",
          "value": "CWE-193"
        }
      ]
    },
    {
      "type": "Secondary",
      "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
      "description": [
        {
          "lang": "en",
          "value": "CWE-193"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Postfix before 3.8.16, 3.9 before 3.9.10, and 3.10 before 3.10.9 sometimes allows a buffer over-read and process crash via an enhanced status code that lacks text after the third number."
    }
  ],
  "lastModified": "2026-08-20T13:18:37.960",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:postfix:postfix:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "439B2155-5F30-42FD-B57A-32B7AC32E2A1",
              "versionEndExcluding": "3.8.16"
            },
            {
              "criteria": "cpe:2.3:a:postfix:postfix:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4AE4398A-5217-408E-BF9B-D3A9ACC0E6C6",
              "versionEndExcluding": "3.9.10",
              "versionStartIncluding": "3.9.0"
            },
            {
              "criteria": "cpe:2.3:a:postfix:postfix:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "0A9CB1E4-A91E-4EC9-9E4E-7F41679EEF13",
              "versionEndExcluding": "3.10.9",
              "versionStartIncluding": "3.10.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve@mitre.org"
}