FKIE_CVE-2026-91769

Vulnerability from fkie_nvd - Published: 2026-09-25 21:17 - Updated: 2026-09-25 21:17
Severity
4.3 (Medium) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Summary
PHP's OpenSSL stream peer verification checks the certificate's subjectAltName entries first and, whenever no entry matches, falls back to the Common Name. RFC 6125 requires the CN to be ignored once the certificate presents any service identity, so a certificate carrying a non-matching DNS SAN was still accepted when its CN matched the requested peer_name. A certificate trusted by the client for one name can therefore be used to impersonate another.
References
security@php.nethttps://github.com/php/php-src/security/advisories/GHSA-vvx9-73fr-5jjx
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "packageName": "ext-openssl",
          "product": "PHP",
          "vendor": "PHP Group",
          "versions": [
            {
              "lessThan": "8.2.34",
              "status": "affected",
              "version": "8.2.*",
              "versionType": "semver"
            },
            {
              "lessThan": "8.3.35",
              "status": "affected",
              "version": "8.3.*",
              "versionType": "semver"
            },
            {
              "lessThan": "8.4.26",
              "status": "affected",
              "version": "8.4.*",
              "versionType": "semver"
            },
            {
              "lessThan": "8.5.11",
              "status": "affected",
              "version": "8.5.*",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "security@php.net"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "PHP\u0027s OpenSSL stream peer verification checks the certificate\u0027s subjectAltName entries first and, whenever no entry matches, falls back to the Common Name. RFC 6125 requires the CN to be ignored once the certificate presents any service identity, so a certificate carrying a non-matching DNS SAN was still accepted when its CN matched the requested peer_name. A certificate trusted by the client for one name can therefore be used to impersonate another."
    }
  ],
  "id": "CVE-2026-91769",
  "lastModified": "2026-09-25T21:17:24.913",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 4.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 1.4,
        "source": "security@php.net",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-25T21:17:24.913",
  "references": [
    {
      "source": "security@php.net",
      "url": "https://github.com/php/php-src/security/advisories/GHSA-vvx9-73fr-5jjx"
    }
  ],
  "sourceIdentifier": "security@php.net",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-297"
        }
      ],
      "source": "security@php.net",
      "type": "Secondary"
    }
  ]
}



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