CVE-2026-120645 — CGI versions before 5.00 for Perl allow denial of service via submitted values used as a regex for optgroup selection in scrolling_list

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": 0.00495,
  "percentile": 0.42971
}

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

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-10",
  "epss": 0.00495,
  "percentile": 0.42798
}

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": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-120645",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-11-09T19:33:39.319914Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-11-09T19:34:11.661Z",
          "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::scrolling_list"
            }
          ],
          "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 denial of service via submitted values used as a regex for optgroup selection in scrolling_list.\n\nWhen rendering option groups, scrolling_list marks the selected options by interpolating each selected value, by default taken from the request parameters, unescaped into a substitution pattern.\n\nA client can make the request die with an invalid pattern, or tie up the process with one that backtracks heavily."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1333",
              "description": "CWE-1333 Inefficient Regular Expression Complexity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-625",
              "description": "CWE-625 Permissive Regular Expression",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-03T23:40:54.754Z",
        "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/824956fbb0c4eb77044ba2dc9180a30df12cb309.patch"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to CGI 5.00 or later."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "CGI versions before 5.00 for Perl allow denial of service via submitted values used as a regex for optgroup selection in scrolling_list",
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-120645",
    "datePublished": "2026-11-03T23:40:54.754Z",
    "dateReserved": "2026-11-02T17:42:57.379Z",
    "dateUpdated": "2026-11-09T19:34:11.661Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}