FKIE_CVE-2026-43820

Vulnerability from fkie_nvd - Published: 2026-07-23 15:17 - Updated: 2026-09-04 18:21
Severity
7.7 (High) - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Summary
NIOSSLCertificate._subjectAlternativeNames provides access to the raw bytes for a cert's SANs. NIOSSL provides access to a buffer assumed to be backed by an ASN1_STRING, but not all SANs are backed by ASN1_STRING, so accessing the buffer for such a type can lead to out-of-bounds memory access. This vulnerability is addressed in swift-nio-ssl version 2.37.2.
References
product-security@apple.comhttps://github.com/apple/swift-nio-ssl/security/advisories/GHSA-xfxg-9975-pc2jVendor Advisory, Exploit
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/apple/swift-nio-ssl/security/advisories/GHSA-xfxg-9975-pc2jVendor Advisory, Exploit
Impacted products
Vendor Product Version
apple swiftnio_ssl *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "swift-nio-ssl",
          "vendor": "Apple",
          "versions": [
            {
              "lessThan": "2.37.2",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "product-security@apple.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:apple:swiftnio_ssl:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "1991D9E3-F794-4A75-85BA-07412FAC0886",
              "versionEndExcluding": "2.37.2",
              "versionStartIncluding": "2.18.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "NIOSSLCertificate._subjectAlternativeNames provides access to the raw bytes for a cert\u0027s SANs. NIOSSL provides access to a buffer assumed to be backed by an ASN1_STRING, but not all SANs are backed by ASN1_STRING, so accessing the buffer for such a type can lead to out-of-bounds memory access. This vulnerability is addressed in swift-nio-ssl version 2.37.2."
    }
  ],
  "id": "CVE-2026-43820",
  "lastModified": "2026-09-04T18:21:10.990",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.7,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.5,
        "impactScore": 5.2,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-43820",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-24T20:09:17.611102Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-23T15:17:05.503",
  "references": [
    {
      "source": "product-security@apple.com",
      "tags": [
        "Vendor Advisory",
        "Exploit"
      ],
      "url": "https://github.com/apple/swift-nio-ssl/security/advisories/GHSA-xfxg-9975-pc2j"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Vendor Advisory",
        "Exploit"
      ],
      "url": "https://github.com/apple/swift-nio-ssl/security/advisories/GHSA-xfxg-9975-pc2j"
    }
  ],
  "sourceIdentifier": "product-security@apple.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}



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