CVE-2026-120647 — CGI versions before 5.00 for Perl allow Content-Disposition parameter injection via unescaped double quotes in the header attachment filename

Exploitation evidence

Not listed in the latest downloaded CISA KEV catalog. This does not establish an absence of exploitation.

KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗

Reported products and versions

/

Default status: unaffected

affected: 0 to < 5.00 (custom)

Fixes and workarounds

Upgrade to CGI 5.00 or later.

Sources and related reporting

CVE Program record ↗ · Download tracked evidence as JSON

Monitored source mentions

BleepingComputer — Microsoft November 2026 Patch Tuesday fixes 1,235 flaws, Outlook zero-day ↗

Shared CVE identifiers link source mentions; they do not establish that the reports describe the same incident.

Observed change timeline

History begins when Egret first downloads each source. It is not the complete upstream CVE history.

12 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-12",
  "epss": 0.00521,
  "percentile": 0.44728
}

11 Nov 2026, 12:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-10",
  "epss": 0.00521,
  "percentile": 0.44555
}

11 Nov 2026, 12:20 Jerusalem · CVE Program record changed

Stored CNA snapshot at this observation.

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 9.8,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-120647",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-11-09T19:37:35.283910Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-11-09T19:37:55.900Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "CGI"
          ],
          "packageName": "CGI",
          "packageURL": "pkg:cpan/CGI",
          "programFiles": [
            "lib/CGI.pm"
          ],
          "programRoutines": [
            {
              "name": "CGI::header"
            }
          ],
          "repo": "https://github.com/leejo/CGI.pm",
          "versions": [
            {
              "lessThan": "5.00",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "CGI versions before 5.00 for Perl allow Content-Disposition parameter injection via unescaped double quotes in the header attachment filename.\n\nheader(-attachment => $name) writes $name into the quoted filename parameter of Content-Disposition without escaping double quotes.\n\nAn application that passes request data as the attachment name can be made to send a second filename parameter, changing the name the response is saved under."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-116",
              "description": "CWE-116 Improper Encoding or Escaping of Output",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-03T23:41:05.454Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://metacpan.org/release/LEEJO/CGI-4.72/source/lib/CGI.pm"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/LEEJO/CGI-5.00/changes"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/leejo/CGI.pm/commit/131280a5c5bc51b65797bd57ef0ee8da8468065b.patch"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to CGI 5.00 or later."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "CGI versions before 5.00 for Perl allow Content-Disposition parameter injection via unescaped double quotes in the header attachment filename",
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-120647",
    "datePublished": "2026-11-03T23:41:05.454Z",
    "dateReserved": "2026-11-02T17:45:23.639Z",
    "dateUpdated": "2026-11-09T19:37:55.900Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}