CVE-2026-110676 (GCVE-0-2026-110676)

Vulnerability from cvelistv5 – Published: 2026-10-19 18:11 – Updated: 2026-10-19 18:11
VLAI
Title
Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by encoding exponent notation as full decimal digits under allow_bignum
Summary
Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by encoding exponent notation as full decimal digits under allow_bignum. With allow_bignum, a JSON number with a fraction or exponent decodes to a Math::BigFloat, which stores the exponent separately and so decodes cheaply. Encoding it untyped or as JSON_TYPE_FLOAT writes the plain decimal form with one digit per unit of exponent. Nothing bounds the exponent, so the 12-byte text [1e30000000] encodes to 30 MB. Untrusted JSON decoded with allow_bignum and encoded again can exhaust memory and CPU.
Severity
No CVSS data available.
CWE
  • CWE-405 - Asymmetric Resource Consumption (Amplification)
Assigner
CPANSec CNA under the redhat root
CNA scorecard C 63/100 over 297 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Affected: 0 , < 4.80 (custom)
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Cpanel::JSON::XS"
          ],
          "packageName": "Cpanel-JSON-XS",
          "packageURL": "pkg:cpan/Cpanel-JSON-XS",
          "programFiles": [
            "XS.xs"
          ],
          "programRoutines": [
            {
              "name": "encode_rv"
            },
            {
              "name": "encode_sv"
            }
          ],
          "repo": "https://github.com/rurban/Cpanel-JSON-XS",
          "versions": [
            {
              "lessThan": "4.80",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by encoding exponent notation as full decimal digits under allow_bignum.\n\nWith allow_bignum, a JSON number with a fraction or exponent decodes to a Math::BigFloat, which stores the exponent separately and so decodes cheaply. Encoding it untyped or as JSON_TYPE_FLOAT writes the plain decimal form with one digit per unit of exponent. Nothing bounds the exponent, so the 12-byte text [1e30000000] encodes to 30 MB.\n\nUntrusted JSON decoded with allow_bignum and encoded again can exhaust memory and CPU."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-405",
              "description": "CWE-405 Asymmetric Resource Consumption (Amplification)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T18:11:45.805Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/rurban/Cpanel-JSON-XS/commit/996ab96972b967a917536d291947b5f3cf42e960.patch"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.80/changes"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to Cpanel-JSON-XS 4.80 or later."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "timeline": [
        {
          "lang": "en",
          "time": "2026-10-14T00:00:00.000Z",
          "value": "Version 4.80 released with fix."
        }
      ],
      "title": "Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by encoding exponent notation as full decimal digits under allow_bignum",
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-110676",
    "datePublished": "2026-10-19T18:11:45.805Z",
    "dateReserved": "2026-10-14T13:23:56.248Z",
    "dateUpdated": "2026-10-19T18:11:45.805Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-110676",
      "date": "2026-10-23",
      "epss": "0.00171",
      "percentile": "0.06176"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "collectionURL": "https://cpan.org/modules",
                "defaultStatus": "unaffected",
                "modules": [
                  "Cpanel::JSON::XS"
                ],
                "packageName": "Cpanel-JSON-XS",
                "packageURL": "pkg:cpan/Cpanel-JSON-XS",
                "programFiles": [
                  "XS.xs"
                ],
                "programRoutines": [
                  {
                    "name": "encode_rv"
                  },
                  {
                    "name": "encode_sv"
                  }
                ],
                "repo": "https://github.com/rurban/Cpanel-JSON-XS",
                "versions": [
                  {
                    "lessThan": "4.80",
                    "status": "affected",
                    "version": "0",
                    "versionType": "custom"
                  }
                ]
              }
            ],
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by encoding exponent notation as full decimal digits under allow_bignum.\n\nWith allow_bignum, a JSON number with a fraction or exponent decodes to a Math::BigFloat, which stores the exponent separately and so decodes cheaply. Encoding it untyped or as JSON_TYPE_FLOAT writes the plain decimal form with one digit per unit of exponent. Nothing bounds the exponent, so the 12-byte text [1e30000000] encodes to 30 MB.\n\nUntrusted JSON decoded with allow_bignum and encoded again can exhaust memory and CPU."
          }
        ],
        "id": "CVE-2026-110676",
        "lastModified": "2026-10-19T20:50:17.967",
        "metrics": {},
        "published": "2026-10-19T19:17:21.320",
        "references": [
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://github.com/rurban/Cpanel-JSON-XS/commit/996ab96972b967a917536d291947b5f3cf42e960.patch"
          },
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.80/changes"
          }
        ],
        "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "vulnStatus": "Awaiting Analysis",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-405"
              }
            ],
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "current_release_date": "2026-10-20T20:59:03+00:00",
      "cve": "CVE-2026-110676",
      "id": "CVE-2026-110676",
      "initial_release_date": "2026-10-19T18:11:45.805000+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "perl-Cpanel-JSON-XS: Memory and CPU exhaustion via allow_bignum exponent encoding",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-110676.json",
      "version": "3"
    }
  }
}



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