CVE-2026-45068: Symfony/mailer Symfony Has An Argument Injection Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-xx3c-qf5g-hc39",
  "modified" : "2026-05-27T20:46:05Z",
  "published" : "2026-05-27T20:46:05Z",
  "aliases" : [ "CVE-2026-45068" ],
  "summary" : "Symfony has an Argument Injection in SendmailTransport via Dash-Prefixed Recipient Address",
  "details" : "### Description\n\nSymfony Mailer selects a transport via the `MAILER_DSN` environment variable / configuration (e.g. `smtp://...`, `sendmail://...`, `native://default`). `SendmailTransport` invokes the local `sendmail` binary and supports two modes: `-bs` (speak SMTP over stdin: the default) and `-t` (read the message on stdin, pass recipients as command-line arguments).\n\nIn `-t` mode, recipient addresses are appended to the sendmail command line **without a `--` end-of-options separator**. A recipient address beginning with `-` (which `Symfony\\Component\\Mime\\Address` accepts as valid) is therefore interpreted by sendmail as a command-line option rather than an address.\n\n### Resolution\n\nThe `SendmailTransport` transport now ensure `--` is set before the list of recipients.\n\nThe patch for this issue is available [here](https://github.com/symfony/symfony/commit/c45144862dc289d03952f41f6078174089a3afc6) for branch 5.4.\n\n### Credits\n\nSymfony 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:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "symfony/mailer"
    },
    "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/mailer"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "6.0.0"
      }, {
        "fixed" : "6.4.40"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "symfony/mailer"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "7.0.0"
      }, {
        "fixed" : "7.4.12"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "symfony/mailer"
    },
    "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-xx3c-qf5g-hc39"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/symfony/symfony/commit/c45144862dc289d03952f41f6078174089a3afc6"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/mailer/CVE-2026-45068.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-45068.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/symfony/symfony"
  }, {
    "type" : "WEB",
    "url" : "https://symfony.com/cve-2026-45068"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-88" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-27T20:46:05Z",
    "nvd_published_at" : null
  }
}