← Back to CVE Explorer

CVE-2026-116269

Full vulnerability record from the local CVENow database.

Description

MIME::Field::ParamVal versions before 5.521 for Perl turn an RFC 2231 filename with a hyphenated language tag into an empty recommended filename. A parameter such as filename*=utf-8'en-US'payload.exe is converted to an encoded word with the language tag appended to the charset. The decoder strips the language suffix only when it is a single word, so it cannot resolve the charset UTF-8*EN-US and returns an empty string. The recommended_filename() method returns that empty string rather than falling back to the name parameter. Other mail readers return payload.exe. A remote sender can get an attachment past a policy that checks file extensions on the recommended filename.

Severity
Not scored
CVSS score
Not available
Vulnerability status
Awaiting Analysis
Source identifier
9b29abf9-4ab0-4765-b253-1875cd9b441e
Published
2026-10-28 18:17:13.363000
Last modified
2026-10-29 15:11:53
View original CVE JSON
{
  "id": "CVE-2026-116269",
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "published": "2026-10-28T18:17:13.363",
  "lastModified": "2026-10-29T15:11:53.000",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "MIME::Field::ParamVal versions before 5.521 for Perl turn an RFC 2231 filename with a hyphenated language tag into an empty recommended filename.\n\nA parameter such as filename*=utf-8'en-US'payload.exe is converted to an encoded word with the language tag appended to the charset. The decoder strips the language suffix only when it is a single word, so it cannot resolve the charset UTF-8*EN-US and returns an empty string. The recommended_filename() method returns that empty string rather than falling back to the name parameter.\n\nOther mail readers return payload.exe. A remote sender can get an attachment past a policy that checks file extensions on the recommended filename."
    }
  ],
  "affected": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "collectionURL": "https://cpan.org/modules",
          "packageName": "MIME-tools",
          "modules": [
            "MIME::Field::ParamVal"
          ],
          "programFiles": [
            "lib/MIME/Field/ParamVal.pm",
            "lib/MIME/WordDecoder.pm",
            "lib/MIME/Head.pm"
          ],
          "programRoutines": [
            {
              "name": "MIME::Field::ParamVal::parse_params"
            },
            {
              "name": "MIME::WordDecoder::decode"
            },
            {
              "name": "MIME::Head::recommended_filename"
            }
          ],
          "repo": "https://salsa.debian.org/dskoll/mime-tools",
          "packageURL": "pkg:cpan/MIME-tools",
          "versions": [
            {
              "version": "0",
              "lessThan": "5.521",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "weaknesses": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-436"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://metacpan.org/release/DSKOLL/MIME-tools-5.521/changes",
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    }
  ]
}