MIME::Parser::FileUnder versions before 5.521 for Perl reuse a pre-created output directory and follow symlinks in it, letting local users redirect attachment writes

{
  "id": "93a8d19c334e4fac724f5e5ee95e5f9a4ffac1fa7245948782cb38a21c59070a",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-116271",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "MIME::Parser::FileUnder versions before 5.521 for Perl reuse a pre-created output directory and follow symlinks in it, letting local users redirect attachment writes",
    "summary": "MIME::Parser::FileUnder versions before 5.521 for Perl reuse a pre-created output directory and follow symlinks in it, letting local users redirect attachment writes. Each message is written to a directory named msg--- under the output base, and an existing directory of that name is used as is. A file name counts as unused when nothing exists at that path, which holds for a dangling symlink, and the body file is then opened in a way that follows the link. When the output base is writable by other users, as with output_under(\"/tmp\"), a local user can pre-create the directory with a symlink named like an attachment. The parser then writes the attachment to the link target with the privileges of the parsing process.",
    "evidence": "cve:CVE-2026-116271",
    "products": [],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-116271",
      "aliases": [
        "CVE-2026-116271"
      ],
      "metrics": [],
      "affected": [
        {
          "repo": "https://salsa.debian.org/dskoll/mime-tools",
          "modules": [
            "MIME::Parser::FileUnder"
          ],
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "5.521",
              "versionType": "custom"
            }
          ],
          "packageURL": "pkg:cpan/MIME-tools",
          "packageName": "MIME-tools",
          "programFiles": [
            "lib/MIME/Parser/Filer.pm",
            "lib/MIME/Body.pm"
          ],
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "programRoutines": [
            {
              "name": "MIME::Parser::FileUnder::init_parse"
            },
            {
              "name": "MIME::Parser::Filer::find_unused_path"
            }
          ]
        }
      ],
      "modified": "2026-10-28T17:34:06.757Z",
      "provider": "cve",
      "references": [
        "https://metacpan.org/release/DSKOLL/MIME-tools-5.521/changes"
      ],
      "provider_metadata": {
        "cna": {
          "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
          "shortName": "CPANSec",
          "dateUpdated": "2026-10-28T17:34:06.757Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-116271",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-cve",
  "document_id": 466447,
  "published_at": "2026-10-28T17:34:06.757+00:00"
}