CVE-2026-45067: Symfony/mime Symfony Has Email Header / Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-qpmx-3rfj-7rhv",
  "modified" : "2026-05-27T20:42:07Z",
  "published" : "2026-05-27T20:42:07Z",
  "aliases" : [ "CVE-2026-45067" ],
  "summary" : "Symfony has Email Header / SMTP Command Injection via CRLF in Symfony\\Component\\Mime\\Address",
  "details" : "### Description\n\n`Symfony\\Component\\Mime\\Address` is the value-object every Symfony Mailer address (to/cc/bcc/from/reply-to) flows through; its constructor is documented as validating the address and throwing on invalid input, so developers treat it as a security boundary.\n\nThe constructor accepts email addresses whose local-part (the part before `@`) is an RFC-5322 *quoted string* containing raw `\\r\\n` bytes, e.g. `\"x\\r\\nBcc: attacker@evil\"@example.com`. The stored address is later emitted verbatim into (1) the rendered message headers and (2) `SmtpTransport`'s `MAIL FROM:<...>` / `RCPT TO:<...>` protocol lines, turning the embedded CRLF into a new mail header and/or a new SMTP command.\n\n### Resolution\n\nThe `Address` constructor now rejects addresses containing line breaks.\n\nThe patch for this issue is available [here](https://github.com/symfony/symfony/commit/dc2dbd29211eb4ddc451373fa1374fb926e94604) for branch 5.4.\n\n### Credits\n\nWe would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "symfony/mime"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.4.52"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "symfony/symfony"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.4.52"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "symfony/mime"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "6.0.0"
      }, {
        "fixed" : "6.4.40"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "symfony/mime"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "7.0.0"
      }, {
        "fixed" : "7.4.12"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "symfony/mime"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.12"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "symfony/symfony"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "6.0.0"
      }, {
        "fixed" : "6.4.40"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "symfony/symfony"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "7.0.0"
      }, {
        "fixed" : "7.4.12"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "symfony/symfony"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.0.12"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/symfony/symfony/security/advisories/GHSA-qpmx-3rfj-7rhv"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/symfony/symfony/commit/dc2dbd29211eb4ddc451373fa1374fb926e94604"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/mime/CVE-2026-45067.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-45067.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/symfony/symfony"
  }, {
    "type" : "WEB",
    "url" : "https://symfony.com/cve-2026-45067"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-93" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-27T20:42:07Z",
    "nvd_published_at" : null
  }
}