CVE-2026-116265

Full vulnerability record from the local CVENow database.

Description

MIME::Field::ParamVal versions before 5.521 for Perl do not flag an ambiguous multipart boundary written as RFC 2231 continuations. The boundary ambiguity checks look only at a plain boundary= parameter, and a boundary split into RFC 2231 sections (boundary*0=, boundary*1= and so on) is joined after they have run. A repeated section number is concatenated rather than reported as a duplicate. From version 5.518, an encoded word or trailing whitespace in such a boundary also goes unflagged, although multipart_boundary() decodes or strips it. A remote sender can make MIME::Parser split a message on a different boundary than other mail readers, hiding an attachment from a filter that relies on ambiguous_content() while the recipient's mail client shows it.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Awaiting Analysis

Source identifier

9b29abf9-4ab0-4765-b253-1875cd9b441e

Published

2026-10-28 18:17:12.910000

Last modified

2026-10-29 15:11:53

View original CVE JSON

{
  "id": "CVE-2026-116265",
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "published": "2026-10-28T18:17:12.910",
  "lastModified": "2026-10-29T15:11:53.000",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "MIME::Field::ParamVal versions before 5.521 for Perl do not flag an ambiguous multipart boundary written as RFC 2231 continuations.\n\nThe boundary ambiguity checks look only at a plain boundary= parameter, and a boundary split into RFC 2231 sections (boundary*0=, boundary*1= and so on) is joined after they have run. A repeated section number is concatenated rather than reported as a duplicate. From version 5.518, an encoded word or trailing whitespace in such a boundary also goes unflagged, although multipart_boundary() decodes or strips it.\n\nA remote sender can make MIME::Parser split a message on a different boundary than other mail readers, hiding an attachment from a filter that relies on ambiguous_content() while the recipient's mail client shows it."
    }
  ],
  "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"
          ],
          "programRoutines": [
            {
              "name": "MIME::Field::ParamVal::parse_params"
            }
          ],
          "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"
    }
  ]
}