GHSA-VQC8-7275-Q272

Vulnerability from github – Published: 2026-05-27 21:09 – Updated: 2026-05-27 21:09
VLAI
Summary
Symfony has Email Header Injection via Non-Token Characters in Mime Parameter Names
Details

Description

Symfony\Component\Mime\Header\ParameterizedHeader (and the related parameter handling reachable from Symfony\Component\Mime\Header\Headers) is responsible for serializing structured headers such as Content-Type and Content-Disposition, which carry key=value parameters (e.g. Content-Disposition: attachment; filename="x").

RFC 2045 / RFC 5322 require parameter names to be tokens: a restricted ASCII subset that excludes whitespace, CR/LF, and the tspecials set. Symfony's parameter handling validates and properly encodes parameter values, but does not validate parameter names: the supplied name is emitted verbatim into the serialized header.

A caller that derives a parameter name from untrusted input, e.g. an application that lets a user influence a Content-Disposition parameter name, can include \r\n or other non-token bytes inside the name, terminating the current header and injecting additional headers in the rendered message. This is the classic CRLF / header-injection primitive applied to the parameter-name slot.

Resolution

ParameterizedHeader now rejects parameter names that contain bytes outside the RFC token character class.

The patch for this issue is available here for branch 5.4.

Credits

Symfony would like to thank Fabian Fleischer for reporting the issue and Alexandre Daubois for fixing it.

Severity
4.9 (Medium)
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/E:U
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/mime"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.4.52"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/symfony"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.4.52"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/mime"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.0.0"
            },
            {
              "fixed": "6.4.40"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/mime"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.0.0"
            },
            {
              "fixed": "7.4.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/mime"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.0.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/symfony"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.0.0"
            },
            {
              "fixed": "6.4.40"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/symfony"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.0.0"
            },
            {
              "fixed": "7.4.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "symfony/symfony"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.0.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-45070"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-93"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-27T21:09:12Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Description\n\n`Symfony\\Component\\Mime\\Header\\ParameterizedHeader` (and the related parameter handling reachable from `Symfony\\Component\\Mime\\Header\\Headers`) is responsible for serializing structured headers such as `Content-Type` and `Content-Disposition`, which carry `key=value` parameters (e.g. `Content-Disposition: attachment; filename=\"x\"`).\n\nRFC 2045 / RFC 5322 require parameter *names* to be `tokens`: a restricted ASCII subset that excludes whitespace, CR/LF, and the `tspecials` set. Symfony\u0027s parameter handling validates and properly encodes parameter *values*, but does not validate parameter *names*: the supplied name is emitted verbatim into the serialized header.\n\nA caller that derives a parameter name from untrusted input, e.g. an application that lets a user influence a `Content-Disposition` parameter name, can include `\\r\\n` or other non-token bytes inside the name, terminating the current header and injecting additional headers in the rendered message. This is the classic CRLF / header-injection primitive applied to the parameter-name slot.\n\n### Resolution\n\n`ParameterizedHeader` now rejects parameter names that contain bytes outside the RFC `token` character class.\n\nThe patch for this issue is available [here](https://github.com/symfony/symfony/commit/e62ea217f8b4ca8ae922ad0f949e0c4dc1f9b613) for branch 5.4.\n\n### Credits\n\nSymfony would like to thank Fabian Fleischer for reporting the issue and Alexandre Daubois for fixing it.",
  "id": "GHSA-vqc8-7275-q272",
  "modified": "2026-05-27T21:09:12Z",
  "published": "2026-05-27T21:09:12Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/symfony/symfony/security/advisories/GHSA-vqc8-7275-q272"
    },
    {
      "type": "WEB",
      "url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/mime/CVE-2026-45070.yaml"
    },
    {
      "type": "WEB",
      "url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-45070.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/symfony/symfony"
    },
    {
      "type": "WEB",
      "url": "https://symfony.com/cve-2026-45070"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "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/E:U",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Symfony has Email Header Injection via Non-Token Characters in Mime Parameter Names"
}



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