Vulnerability-Lookup

CVE-2026-87080 (GCVE-0-2026-87080)

Vulnerability from cvelistv5 – Published: 2026-09-22 07:25 – Updated: 2026-09-22 07:25

Title

Net::IDN::Punycode::PP versions before 2.590 for Perl decode a truncated label to a name containing a character it never encoded in decode_punycode

Summary

Net::IDN::Punycode::PP versions before 2.590 for Perl decode a truncated label to a name containing a character it never encoded in decode_punycode. The pure-Perl decoder reads one digit at a time with four-argument substr and tests the result with defined to detect the end of the input. substr on an exhausted string returns the empty string rather than undef, so decoding continues past the end. The empty string converts to a digit value below the range, reducing the accumulator, and the decoder derives one extra code point and its position from it. The result is deterministic. The XS backend rejects the same label. Net::IDN::Punycode uses this backend wherever the XS does not build. The two backends disagree about what such a label means, so a sender can pick a label that one installation resolves to a name and another rejects.

Severity

No CVSS data available.

CWE

CWE-1286 - Improper Validation of Syntactic Correctness of Input

Assigner

CPANSec redhat root

References

2 references

URL	Tags
https://metacpan.org/release/PJCJ/Net-IDN-Encode-…	release-notes
https://github.com/robrwo/Net-IDN-Encode/commit/4…	patch

Impacted products

1 product

Vendor	Product	Version	CPE status
		Affected: 0 , < 2.590 (custom)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Net::IDN::Punycode::PP"
          ],
          "packageName": "Net-IDN-Encode",
          "packageURL": "pkg:cpan/Net-IDN-Encode",
          "programFiles": [
            "lib/Net/IDN/Punycode/PP.pm"
          ],
          "programRoutines": [
            {
              "name": "Net::IDN::Punycode::PP::decode_punycode"
            }
          ],
          "repo": "https://github.com/robrwo/Net-IDN-Encode",
          "versions": [
            {
              "lessThan": "2.590",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Net::IDN::Punycode::PP versions before 2.590 for Perl decode a truncated label to a name containing a character it never encoded in decode_punycode.\n\nThe pure-Perl decoder reads one digit at a time with four-argument substr and tests the result with defined to detect the end of the input. substr on an exhausted string returns the empty string rather than undef, so decoding continues past the end. The empty string converts to a digit value below the range, reducing the accumulator, and the decoder derives one extra code point and its position from it. The result is deterministic. The XS backend rejects the same label.\n\nNet::IDN::Punycode uses this backend wherever the XS does not build.\n\nThe two backends disagree about what such a label means, so a sender can pick a label that one installation resolves to a name and another rejects."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1286",
              "description": "CWE-1286 Improper Validation of Syntactic Correctness of Input",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-22T07:25:03.236Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/robrwo/Net-IDN-Encode/commit/48436c7ad2c4d4c6398110e11133754fc476a783.patch"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to Net-IDN-Encode 2.590-TRIAL or later."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Net::IDN::Punycode::PP versions before 2.590 for Perl decode a truncated label to a name containing a character it never encoded in decode_punycode",
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-87080",
    "datePublished": "2026-09-22T07:25:03.236Z",
    "dateReserved": "2026-09-08T19:22:20.005Z",
    "dateUpdated": "2026-09-22T07:25:03.236Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "collectionURL": "https://cpan.org/modules",
                "defaultStatus": "unaffected",
                "modules": [
                  "Net::IDN::Punycode::PP"
                ],
                "packageName": "Net-IDN-Encode",
                "packageURL": "pkg:cpan/Net-IDN-Encode",
                "programFiles": [
                  "lib/Net/IDN/Punycode/PP.pm"
                ],
                "programRoutines": [
                  {
                    "name": "Net::IDN::Punycode::PP::decode_punycode"
                  }
                ],
                "repo": "https://github.com/robrwo/Net-IDN-Encode",
                "versions": [
                  {
                    "lessThan": "2.590",
                    "status": "affected",
                    "version": "0",
                    "versionType": "custom"
                  }
                ]
              }
            ],
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Net::IDN::Punycode::PP versions before 2.590 for Perl decode a truncated label to a name containing a character it never encoded in decode_punycode.\n\nThe pure-Perl decoder reads one digit at a time with four-argument substr and tests the result with defined to detect the end of the input. substr on an exhausted string returns the empty string rather than undef, so decoding continues past the end. The empty string converts to a digit value below the range, reducing the accumulator, and the decoder derives one extra code point and its position from it. The result is deterministic. The XS backend rejects the same label.\n\nNet::IDN::Punycode uses this backend wherever the XS does not build.\n\nThe two backends disagree about what such a label means, so a sender can pick a label that one installation resolves to a name and another rejects."
          }
        ],
        "id": "CVE-2026-87080",
        "lastModified": "2026-09-22T08:16:40.750",
        "metrics": {},
        "published": "2026-09-22T08:16:40.750",
        "references": [
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://github.com/robrwo/Net-IDN-Encode/commit/48436c7ad2c4d4c6398110e11133754fc476a783.patch"
          },
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes"
          }
        ],
        "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "vulnStatus": "Received",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-1286"
              }
            ],
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "type": "Secondary"
          }
        ]
      }
    }
  }
}

FKIE_CVE-2026-87080

Vulnerability from fkie_nvd - Published: 2026-09-22 08:16 - Updated: 2026-09-22 08:16

Severity

Summary

References

	URL	Tags
	9b29abf9-4ab0-4765-b253-1875cd9b441e	https://github.com/robrwo/Net-IDN-Encode/commit/48436c7ad2c4d4c6398110e11133754fc476a783.patch
	9b29abf9-4ab0-4765-b253-1875cd9b441e	https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Net::IDN::Punycode::PP"
          ],
          "packageName": "Net-IDN-Encode",
          "packageURL": "pkg:cpan/Net-IDN-Encode",
          "programFiles": [
            "lib/Net/IDN/Punycode/PP.pm"
          ],
          "programRoutines": [
            {
              "name": "Net::IDN::Punycode::PP::decode_punycode"
            }
          ],
          "repo": "https://github.com/robrwo/Net-IDN-Encode",
          "versions": [
            {
              "lessThan": "2.590",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Net::IDN::Punycode::PP versions before 2.590 for Perl decode a truncated label to a name containing a character it never encoded in decode_punycode.\n\nThe pure-Perl decoder reads one digit at a time with four-argument substr and tests the result with defined to detect the end of the input. substr on an exhausted string returns the empty string rather than undef, so decoding continues past the end. The empty string converts to a digit value below the range, reducing the accumulator, and the decoder derives one extra code point and its position from it. The result is deterministic. The XS backend rejects the same label.\n\nNet::IDN::Punycode uses this backend wherever the XS does not build.\n\nThe two backends disagree about what such a label means, so a sender can pick a label that one installation resolves to a name and another rejects."
    }
  ],
  "id": "CVE-2026-87080",
  "lastModified": "2026-09-22T08:16:40.750",
  "metrics": {},
  "published": "2026-09-22T08:16:40.750",
  "references": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://github.com/robrwo/Net-IDN-Encode/commit/48436c7ad2c4d4c6398110e11133754fc476a783.patch"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes"
    }
  ],
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-1286"
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary"
    }
  ]
}

GHSA-M8C4-89QH-3J3F

Vulnerability from github – Published: 2026-09-22 09:31 – Updated: 2026-09-22 09:31

Details

Net::IDN::Punycode::PP versions before 2.590 for Perl decode a truncated label to a name containing a character it never encoded in decode_punycode.

The pure-Perl decoder reads one digit at a time with four-argument substr and tests the result with defined to detect the end of the input. substr on an exhausted string returns the empty string rather than undef, so decoding continues past the end. The empty string converts to a digit value below the range, reducing the accumulator, and the decoder derives one extra code point and its position from it. The result is deterministic. The XS backend rejects the same label.

Net::IDN::Punycode uses this backend wherever the XS does not build.

The two backends disagree about what such a label means, so a sender can pick a label that one installation resolves to a name and another rejects.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-87080"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1286"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-22T08:16:40Z",
    "severity": null
  },
  "details": "Net::IDN::Punycode::PP versions before 2.590 for Perl decode a truncated label to a name containing a character it never encoded in decode_punycode.\n\nThe pure-Perl decoder reads one digit at a time with four-argument substr and tests the result with defined to detect the end of the input. substr on an exhausted string returns the empty string rather than undef, so decoding continues past the end. The empty string converts to a digit value below the range, reducing the accumulator, and the decoder derives one extra code point and its position from it. The result is deterministic. The XS backend rejects the same label.\n\nNet::IDN::Punycode uses this backend wherever the XS does not build.\n\nThe two backends disagree about what such a label means, so a sender can pick a label that one installation resolves to a name and another rejects.",
  "id": "GHSA-m8c4-89qh-3j3f",
  "modified": "2026-09-22T09:31:13Z",
  "published": "2026-09-22T09:31:12Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-87080"
    },
    {
      "type": "WEB",
      "url": "https://github.com/robrwo/Net-IDN-Encode/commit/48436c7ad2c4d4c6398110e11133754fc476a783.patch"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-87080 (GCVE-0-2026-87080)

FKIE_CVE-2026-87080

GHSA-M8C4-89QH-3J3F

Tags

Sightings

Nomenclature

Related by attack behaviour