Vulnerability-Lookup

CVE-2026-74765 (GCVE-0-2026-74765)

Vulnerability from cvelistv5 – Published: 2026-09-22 07:18 – Updated: 2026-09-22 17:07

Title

Net::IDN::Punycode versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode

Summary

Net::IDN::Punycode versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode. The XS backend keeps the punycode delta, and the digit index derived from it, in a signed int. The accumulation `delta += (m-n) * (h+1)` has no overflow check, so a large enough code point wraps the delta and the digit index leaves the range of the 36-entry digit table. The bound before the final table access tests only for an index above 36, so a negative index passes it, as does 36 itself. Perl strings hold code points beyond the Unicode range, and one such code point overflows the accumulation on its own. Valid input wraps it as well, for example 1927 ASCII letters followed by U+10FFFF. The conversion functions encode a label before they check its length, so a long label reaches the encoder through the documented API. Only the XS backend is affected. Encoding an attacker-supplied string copies a byte from outside the digit table into the encoded result or crashes the process.

Severity

6.5 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-22 13:50 UTC

CWE

CWE-190 - Integer Overflow or Wraparound
CWE-125 - Out-of-bounds Read

Assigner

CPANSec redhat root

References

6 references

URL	Tags
https://metacpan.org/release/PJCJ/Net-IDN-Encode-…	release-notes
https://github.com/robrwo/Net-IDN-Encode/commit/2…	patch
https://github.com/robrwo/Net-IDN-Encode/commit/8…	patch
https://github.com/robrwo/Net-IDN-Encode/commit/8…	patch
https://datatracker.ietf.org/doc/html/rfc3492#sec…	technical-description
http://www.openwall.com/lists/oss-security/2026/0…

Impacted products

1 product

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

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "LOW",
              "baseScore": 6.5,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "LOW",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-74765",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-22T13:50:07.818961Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-22T13:57:00.272Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "providerMetadata": {
          "dateUpdated": "2026-09-22T17:07:26.038Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/09/22/11"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Net::IDN::Punycode"
          ],
          "packageName": "Net-IDN-Encode",
          "packageURL": "pkg:cpan/Net-IDN-Encode",
          "programFiles": [
            "lib/Net/IDN/Punycode.xs"
          ],
          "programRoutines": [
            {
              "name": "Net::IDN::Punycode::encode_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 versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode.\n\nThe XS backend keeps the punycode delta, and the digit index derived from it, in a signed int. The accumulation `delta += (m-n) * (h+1)` has no overflow check, so a large enough code point wraps the delta and the digit index leaves the range of the 36-entry digit table. The bound before the final table access tests only for an index above 36, so a negative index passes it, as does 36 itself. Perl strings hold code points beyond the Unicode range, and one such code point overflows the accumulation on its own. Valid input wraps it as well, for example 1927 ASCII letters followed by U+10FFFF. The conversion functions encode a label before they check its length, so a long label reaches the encoder through the documented API.\n\nOnly the XS backend is affected.\n\nEncoding an attacker-supplied string copies a byte from outside the digit table into the encoded result or crashes the process."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-190",
              "description": "CWE-190 Integer Overflow or Wraparound",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-125",
              "description": "CWE-125 Out-of-bounds Read",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-22T07:18:46.087Z",
        "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/27a91ccdb6c9b41f75ba198f5ae154d14e225de2.patch"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/robrwo/Net-IDN-Encode/commit/81c7f99fe7430bdc5116081508dffdb56f376861.patch"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/robrwo/Net-IDN-Encode/commit/89d5aa8d3504c5e96061ab76d1541a89c16157cf.patch"
        },
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://datatracker.ietf.org/doc/html/rfc3492#section-6.4"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to Net-IDN-Encode 2.590-TRIAL or later."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Net::IDN::Punycode versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode",
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-74765",
    "datePublished": "2026-09-22T07:18:46.087Z",
    "dateReserved": "2026-08-15T21:52:57.406Z",
    "dateUpdated": "2026-09-22T17:07:26.038Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-74765",
      "date": "2026-09-23",
      "epss": "0.00296",
      "percentile": "0.22548"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "collectionURL": "https://cpan.org/modules",
                "defaultStatus": "unaffected",
                "modules": [
                  "Net::IDN::Punycode"
                ],
                "packageName": "Net-IDN-Encode",
                "packageURL": "pkg:cpan/Net-IDN-Encode",
                "programFiles": [
                  "lib/Net/IDN/Punycode.xs"
                ],
                "programRoutines": [
                  {
                    "name": "Net::IDN::Punycode::encode_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 versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode.\n\nThe XS backend keeps the punycode delta, and the digit index derived from it, in a signed int. The accumulation `delta += (m-n) * (h+1)` has no overflow check, so a large enough code point wraps the delta and the digit index leaves the range of the 36-entry digit table. The bound before the final table access tests only for an index above 36, so a negative index passes it, as does 36 itself. Perl strings hold code points beyond the Unicode range, and one such code point overflows the accumulation on its own. Valid input wraps it as well, for example 1927 ASCII letters followed by U+10FFFF. The conversion functions encode a label before they check its length, so a long label reaches the encoder through the documented API.\n\nOnly the XS backend is affected.\n\nEncoding an attacker-supplied string copies a byte from outside the digit table into the encoded result or crashes the process."
          }
        ],
        "id": "CVE-2026-74765",
        "lastModified": "2026-09-22T19:07:00.983",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "LOW",
                "baseScore": 6.5,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "LOW",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 2.5,
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-74765",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "yes"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-22T13:50:07.818961Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-09-22T08:16:40.143",
        "references": [
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://datatracker.ietf.org/doc/html/rfc3492#section-6.4"
          },
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://github.com/robrwo/Net-IDN-Encode/commit/27a91ccdb6c9b41f75ba198f5ae154d14e225de2.patch"
          },
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://github.com/robrwo/Net-IDN-Encode/commit/81c7f99fe7430bdc5116081508dffdb56f376861.patch"
          },
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://github.com/robrwo/Net-IDN-Encode/commit/89d5aa8d3504c5e96061ab76d1541a89c16157cf.patch"
          },
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "http://www.openwall.com/lists/oss-security/2026/09/22/11"
          }
        ],
        "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "vulnStatus": "Deferred",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-125"
              },
              {
                "lang": "en",
                "value": "CWE-190"
              }
            ],
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "type": "Secondary"
          }
        ]
      }
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "providerMetadata": {
              "dateUpdated": "2026-09-22T17:07:26.038Z",
              "orgId": "af854a3a-2127-422b-91ae-364da2661108",
              "shortName": "CVE"
            },
            "references": [
              {
                "url": "http://www.openwall.com/lists/oss-security/2026/09/22/11"
              }
            ],
            "title": "CVE Program Container"
          },
          {
            "metrics": [
              {
                "cvssV3_1": {
                  "attackComplexity": "LOW",
                  "attackVector": "NETWORK",
                  "availabilityImpact": "LOW",
                  "baseScore": 6.5,
                  "baseSeverity": "MEDIUM",
                  "confidentialityImpact": "LOW",
                  "integrityImpact": "NONE",
                  "privilegesRequired": "NONE",
                  "scope": "UNCHANGED",
                  "userInteraction": "NONE",
                  "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L",
                  "version": "3.1"
                }
              },
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-74765",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-09-22T13:50:07.818961Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-09-22T13:50:03.316Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "collectionURL": "https://cpan.org/modules",
              "defaultStatus": "unaffected",
              "modules": [
                "Net::IDN::Punycode"
              ],
              "packageName": "Net-IDN-Encode",
              "packageURL": "pkg:cpan/Net-IDN-Encode",
              "programFiles": [
                "lib/Net/IDN/Punycode.xs"
              ],
              "programRoutines": [
                {
                  "name": "Net::IDN::Punycode::encode_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 versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode.\n\nThe XS backend keeps the punycode delta, and the digit index derived from it, in a signed int. The accumulation `delta += (m-n) * (h+1)` has no overflow check, so a large enough code point wraps the delta and the digit index leaves the range of the 36-entry digit table. The bound before the final table access tests only for an index above 36, so a negative index passes it, as does 36 itself. Perl strings hold code points beyond the Unicode range, and one such code point overflows the accumulation on its own. Valid input wraps it as well, for example 1927 ASCII letters followed by U+10FFFF. The conversion functions encode a label before they check its length, so a long label reaches the encoder through the documented API.\n\nOnly the XS backend is affected.\n\nEncoding an attacker-supplied string copies a byte from outside the digit table into the encoded result or crashes the process."
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-190",
                  "description": "CWE-190 Integer Overflow or Wraparound",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            },
            {
              "descriptions": [
                {
                  "cweId": "CWE-125",
                  "description": "CWE-125 Out-of-bounds Read",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-09-22T07:18:46.087Z",
            "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/27a91ccdb6c9b41f75ba198f5ae154d14e225de2.patch"
            },
            {
              "tags": [
                "patch"
              ],
              "url": "https://github.com/robrwo/Net-IDN-Encode/commit/81c7f99fe7430bdc5116081508dffdb56f376861.patch"
            },
            {
              "tags": [
                "patch"
              ],
              "url": "https://github.com/robrwo/Net-IDN-Encode/commit/89d5aa8d3504c5e96061ab76d1541a89c16157cf.patch"
            },
            {
              "tags": [
                "technical-description"
              ],
              "url": "https://datatracker.ietf.org/doc/html/rfc3492#section-6.4"
            }
          ],
          "solutions": [
            {
              "lang": "en",
              "value": "Upgrade to Net-IDN-Encode 2.590-TRIAL or later."
            }
          ],
          "source": {
            "discovery": "UNKNOWN"
          },
          "title": "Net::IDN::Punycode versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode",
          "x_generator": {
            "engine": "cpansec-cna-tool 0.1"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "assignerShortName": "CPANSec",
        "cveId": "CVE-2026-74765",
        "datePublished": "2026-09-22T07:18:46.087Z",
        "dateReserved": "2026-08-15T21:52:57.406Z",
        "dateUpdated": "2026-09-22T17:07:26.038Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}

FKIE_CVE-2026-74765

Vulnerability from fkie_nvd - Published: 2026-09-22 08:16 - Updated: 2026-09-22 19:07

Severity

6.5 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

Summary

References

	URL	Tags
	9b29abf9-4ab0-4765-b253-1875cd9b441e	https://datatracker.ietf.org/doc/html/rfc3492#section-6.4
	9b29abf9-4ab0-4765-b253-1875cd9b441e	https://github.com/robrwo/Net-IDN-Encode/commit/27a91ccdb6c9b41f75ba198f5ae154d14e225de2.patch
	9b29abf9-4ab0-4765-b253-1875cd9b441e	https://github.com/robrwo/Net-IDN-Encode/commit/81c7f99fe7430bdc5116081508dffdb56f376861.patch
	9b29abf9-4ab0-4765-b253-1875cd9b441e	https://github.com/robrwo/Net-IDN-Encode/commit/89d5aa8d3504c5e96061ab76d1541a89c16157cf.patch
	9b29abf9-4ab0-4765-b253-1875cd9b441e	https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes
	af854a3a-2127-422b-91ae-364da2661108	http://www.openwall.com/lists/oss-security/2026/09/22/11

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Net::IDN::Punycode"
          ],
          "packageName": "Net-IDN-Encode",
          "packageURL": "pkg:cpan/Net-IDN-Encode",
          "programFiles": [
            "lib/Net/IDN/Punycode.xs"
          ],
          "programRoutines": [
            {
              "name": "Net::IDN::Punycode::encode_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 versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode.\n\nThe XS backend keeps the punycode delta, and the digit index derived from it, in a signed int. The accumulation `delta += (m-n) * (h+1)` has no overflow check, so a large enough code point wraps the delta and the digit index leaves the range of the 36-entry digit table. The bound before the final table access tests only for an index above 36, so a negative index passes it, as does 36 itself. Perl strings hold code points beyond the Unicode range, and one such code point overflows the accumulation on its own. Valid input wraps it as well, for example 1927 ASCII letters followed by U+10FFFF. The conversion functions encode a label before they check its length, so a long label reaches the encoder through the documented API.\n\nOnly the XS backend is affected.\n\nEncoding an attacker-supplied string copies a byte from outside the digit table into the encoded result or crashes the process."
    }
  ],
  "id": "CVE-2026-74765",
  "lastModified": "2026-09-22T19:07:00.983",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 2.5,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-74765",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-22T13:50:07.818961Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-22T08:16:40.143",
  "references": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://datatracker.ietf.org/doc/html/rfc3492#section-6.4"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://github.com/robrwo/Net-IDN-Encode/commit/27a91ccdb6c9b41f75ba198f5ae154d14e225de2.patch"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://github.com/robrwo/Net-IDN-Encode/commit/81c7f99fe7430bdc5116081508dffdb56f376861.patch"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://github.com/robrwo/Net-IDN-Encode/commit/89d5aa8d3504c5e96061ab76d1541a89c16157cf.patch"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/09/22/11"
    }
  ],
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        },
        {
          "lang": "en",
          "value": "CWE-190"
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary"
    }
  ]
}

GHSA-XW3Q-MP5H-P8JX

Vulnerability from github – Published: 2026-09-22 09:31 – Updated: 2026-09-22 18:33

Details

Net::IDN::Punycode versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode.

The XS backend keeps the punycode delta, and the digit index derived from it, in a signed int. The accumulation delta += (m-n) * (h+1) has no overflow check, so a large enough code point wraps the delta and the digit index leaves the range of the 36-entry digit table. The bound before the final table access tests only for an index above 36, so a negative index passes it, as does 36 itself. Perl strings hold code points beyond the Unicode range, and one such code point overflows the accumulation on its own. Valid input wraps it as well, for example 1927 ASCII letters followed by U+10FFFF. The conversion functions encode a label before they check its length, so a long label reaches the encoder through the documented API.

Only the XS backend is affected.

Encoding an attacker-supplied string copies a byte from outside the digit table into the encoded result or crashes the process.

Severity

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-74765"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-125"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-22T08:16:40Z",
    "severity": "MODERATE"
  },
  "details": "Net::IDN::Punycode versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode.\n\nThe XS backend keeps the punycode delta, and the digit index derived from it, in a signed int. The accumulation `delta += (m-n) * (h+1)` has no overflow check, so a large enough code point wraps the delta and the digit index leaves the range of the 36-entry digit table. The bound before the final table access tests only for an index above 36, so a negative index passes it, as does 36 itself. Perl strings hold code points beyond the Unicode range, and one such code point overflows the accumulation on its own. Valid input wraps it as well, for example 1927 ASCII letters followed by U+10FFFF. The conversion functions encode a label before they check its length, so a long label reaches the encoder through the documented API.\n\nOnly the XS backend is affected.\n\nEncoding an attacker-supplied string copies a byte from outside the digit table into the encoded result or crashes the process.",
  "id": "GHSA-xw3q-mp5h-p8jx",
  "modified": "2026-09-22T18:33:27Z",
  "published": "2026-09-22T09:31:12Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74765"
    },
    {
      "type": "WEB",
      "url": "https://github.com/robrwo/Net-IDN-Encode/commit/27a91ccdb6c9b41f75ba198f5ae154d14e225de2.patch"
    },
    {
      "type": "WEB",
      "url": "https://github.com/robrwo/Net-IDN-Encode/commit/81c7f99fe7430bdc5116081508dffdb56f376861.patch"
    },
    {
      "type": "WEB",
      "url": "https://github.com/robrwo/Net-IDN-Encode/commit/89d5aa8d3504c5e96061ab76d1541a89c16157cf.patch"
    },
    {
      "type": "WEB",
      "url": "https://datatracker.ietf.org/doc/html/rfc3492#section-6.4"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/09/22/11"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L",
      "type": "CVSS_V3"
    }
  ]
}

UBUNTU-CVE-2026-74765 (CVE-2026-74765)

Vulnerability from osv_ubuntu – Published: 2026-09-22 00:00 – Updated: 2026-09-22 00:00 – Source website

Details

Net::IDN::Punycode versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode. The XS backend keeps the punycode delta, and the digit index derived from it, in a signed int. The accumulation delta += (m-n) * (h+1) has no overflow check, so a large enough code point wraps the delta and the digit index leaves the range of the 36-entry digit table. The bound before the final table access tests only for an index above 36, so a negative index passes it, as does 36 itself. Perl strings hold code points beyond the Unicode range, and one such code point overflows the accumulation on its own. Valid input wraps it as well, for example 1927 ASCII letters followed by U+10FFFF. The conversion functions encode a label before they check its length, so a long label reaches the encoder through the documented API. Only the XS backend is affected. Encoding an attacker-supplied string copies a byte from outside the digit table into the encoded result or crashes the process.

Severity

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-74765	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-74765	REPORT
	https://lists.security.metacpan.org/cve-announce/…	REPORT
	https://datatracker.ietf.org/doc/html/rfc3492#sec…	REPORT
	https://github.com/robrwo/Net-IDN-Encode/commit/2…	REPORT
	https://github.com/robrwo/Net-IDN-Encode/commit/8…	REPORT
	https://github.com/robrwo/Net-IDN-Encode/commit/8…	REPORT
	https://metacpan.org/release/PJCJ/Net-IDN-Encode-…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnet-idn-encode-perl",
            "binary_version": "2.300-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "libnet-idn-encode-perl",
        "purl": "pkg:deb/ubuntu/libnet-idn-encode-perl@2.300-1build1?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.202-1",
        "2.300-1",
        "2.300-1build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnet-idn-encode-perl",
            "binary_version": "2.400-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "libnet-idn-encode-perl",
        "purl": "pkg:deb/ubuntu/libnet-idn-encode-perl@2.400-1build1?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.400-1build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnet-idn-encode-perl",
            "binary_version": "2.500-1build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "libnet-idn-encode-perl",
        "purl": "pkg:deb/ubuntu/libnet-idn-encode-perl@2.500-1build1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.500-1",
        "2.500-1build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnet-idn-encode-perl",
            "binary_version": "2.500-2build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libnet-idn-encode-perl",
        "purl": "pkg:deb/ubuntu/libnet-idn-encode-perl@2.500-2build1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.500-1build2",
        "2.500-2",
        "2.500-2build1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnet-idn-encode-perl",
            "binary_version": "2.500-5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libnet-idn-encode-perl",
        "purl": "pkg:deb/ubuntu/libnet-idn-encode-perl@2.500-5?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.500-3",
        "2.500-3build1",
        "2.500-3build2",
        "2.500-5"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libnet-idn-encode-perl",
            "binary_version": "2.500-5build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libnet-idn-encode-perl",
        "purl": "pkg:deb/ubuntu/libnet-idn-encode-perl@2.500-5build1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.500-5build1"
      ]
    }
  ],
  "aliases": [],
  "details": "Net::IDN::Punycode versions before 2.590 for Perl allow an out-of-bounds read via integer overflow of the delta accumulator in encode_punycode. The XS backend keeps the punycode delta, and the digit index derived from it, in a signed int. The accumulation `delta += (m-n) * (h+1)` has no overflow check, so a large enough code point wraps the delta and the digit index leaves the range of the 36-entry digit table. The bound before the final table access tests only for an index above 36, so a negative index passes it, as does 36 itself. Perl strings hold code points beyond the Unicode range, and one such code point overflows the accumulation on its own. Valid input wraps it as well, for example 1927 ASCII letters followed by U+10FFFF. The conversion functions encode a label before they check its length, so a long label reaches the encoder through the documented API. Only the XS backend is affected. Encoding an attacker-supplied string copies a byte from outside the digit table into the encoded result or crashes the process.",
  "id": "UBUNTU-CVE-2026-74765",
  "modified": "2026-09-22T00:00:00Z",
  "published": "2026-09-22T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-74765"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-74765"
    },
    {
      "type": "REPORT",
      "url": "https://lists.security.metacpan.org/cve-announce/msg/43753029/"
    },
    {
      "type": "REPORT",
      "url": "https://datatracker.ietf.org/doc/html/rfc3492#section-6.4"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/robrwo/Net-IDN-Encode/commit/27a91ccdb6c9b41f75ba198f5ae154d14e225de2.patch"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/robrwo/Net-IDN-Encode/commit/81c7f99fe7430bdc5116081508dffdb56f376861.patch"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/robrwo/Net-IDN-Encode/commit/89d5aa8d3504c5e96061ab76d1541a89c16157cf.patch"
    },
    {
      "type": "REPORT",
      "url": "https://metacpan.org/release/PJCJ/Net-IDN-Encode-2.590-TRIAL/changes"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-74765"
  ]
}

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-2026-74765 (GCVE-0-2026-74765)

FKIE_CVE-2026-74765

GHSA-XW3Q-MP5H-P8JX

UBUNTU-CVE-2026-74765 (CVE-2026-74765)

Tags

Sightings

Nomenclature

Related by attack behaviour