Vulnerability-Lookup

ubuntu-cve-2026-19953

Vulnerability from osv_ubuntu

Published

2026-08-27 00:00

Modified

2026-08-27 00:00

Summary

Details

[Unknown description]

Severity

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-19953	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-19953	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "liburi-perl",
            "binary_version": "1.60-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:14.04:LTS",
        "name": "liburi-perl",
        "purl": "pkg:deb/ubuntu/liburi-perl@1.60-1?arch=source\u0026distro=trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.60-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "liburi-perl",
            "binary_version": "1.71-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "liburi-perl",
        "purl": "pkg:deb/ubuntu/liburi-perl@1.71-1?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.69-1",
        "1.71-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "liburi-perl",
            "binary_version": "1.73-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "liburi-perl",
        "purl": "pkg:deb/ubuntu/liburi-perl@1.73-1?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.72-1",
        "1.72-2",
        "1.73-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "liburi-perl",
            "binary_version": "1.76-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "liburi-perl",
        "purl": "pkg:deb/ubuntu/liburi-perl@1.76-2?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.76-1",
        "1.76-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "liburi-perl",
            "binary_version": "5.10-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "liburi-perl",
        "purl": "pkg:deb/ubuntu/liburi-perl@5.10-1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.08-1",
        "5.10-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "liburi-perl",
            "binary_version": "5.27-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "liburi-perl",
        "purl": "pkg:deb/ubuntu/liburi-perl@5.27-1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.19-2",
        "5.21-1",
        "5.25-1",
        "5.27-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "liburi-perl",
            "binary_version": "5.34-2build1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "liburi-perl",
        "purl": "pkg:deb/ubuntu/liburi-perl@5.34-2build1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.30-1",
        "5.34-2build1"
      ]
    }
  ],
  "aliases": [],
  "details": "[Unknown description]",
  "id": "UBUNTU-CVE-2026-19953",
  "modified": "2026-08-27T00:00:00Z",
  "published": "2026-08-27T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-19953"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-19953"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-19953"
  ]
}

CVE-2026-19953 (GCVE-0-2026-19953)

Vulnerability from cvelistv5 – Published: 2026-08-31 17:29 – Updated: 2026-08-31 20:07

Title

URI versions before 5.36 for Perl encode non-NFC host names to non-standard punycode labels via missing normalization in nameprep

Summary

URI versions before 5.36 for Perl encode non-NFC host names to non-standard punycode labels via missing normalization in nameprep. nameprep lowercases each host label but performs no Unicode normalization. IDNA requires a label to be normalized to Form C before it is encoded (RFC 5891), so a label that is not already in NFC is encoded to a different A-label than its normalized form. A label built from the precomposed Devanagari sequence U+0958 U+093E encodes to xn--72b5c without normalization but to xn--11b2fg after NFC normalization, and xn--72b5c does not round-trip back to the original label. Any caller that reads host() from a URI built from untrusted input and uses it for a security decision (an allow or deny list, an SSRF filter, deduplication, a cache key) sees the non-standard label, while a client that fetches the same URL resolves the NFC form, so the check and the fetch can disagree about the host.

Severity

No CVSS data available.

CWE

CWE-1289 - Improper Validation of Unsafe Equivalence in Input

Assigner

CPANSec redhat root

References

5 references

URL	Tags
https://github.com/libwww-perl/URI/commit/956619a…	patch
https://github.com/libwww-perl/URI/pull/191	issue-tracking
https://metacpan.org/release/OALDERS/URI-5.36/changes	release-notes
https://www.rfc-editor.org/rfc/rfc5891#section-5.2	technical-description
http://www.openwall.com/lists/oss-security/2026/0…

Impacted products

1 product

Vendor	Product	Version
		Affected: 0 , < 5.36 (custom)

Credits

Naseeb Dangi (naseeb0), Nankai University

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-08-31T20:07:50.422Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/08/31/14"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "URI"
          ],
          "packageName": "URI",
          "packageURL": "pkg:cpan/URI",
          "programFiles": [
            "lib/URI/_idna.pm"
          ],
          "programRoutines": [
            {
              "name": "URI::_idna::nameprep"
            }
          ],
          "repo": "https://github.com/libwww-perl/URI",
          "versions": [
            {
              "lessThan": "5.36",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Naseeb Dangi (naseeb0), Nankai University"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "URI versions before 5.36 for Perl encode non-NFC host names to non-standard punycode labels via missing normalization in nameprep.\n\nnameprep lowercases each host label but performs no Unicode normalization. IDNA requires a label to be normalized to Form C before it is encoded (RFC 5891), so a label that is not already in NFC is encoded to a different A-label than its normalized form. A label built from the precomposed Devanagari sequence U+0958 U+093E encodes to xn--72b5c without normalization but to xn--11b2fg after NFC normalization, and xn--72b5c does not round-trip back to the original label.\n\nAny caller that reads host() from a URI built from untrusted input and uses it for a security decision (an allow or deny list, an SSRF filter, deduplication, a cache key) sees the non-standard label, while a client that fetches the same URL resolves the NFC form, so the check and the fetch can disagree about the host."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1289",
              "description": "CWE-1289 Improper Validation of Unsafe Equivalence in Input",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-31T17:29:42.929Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/libwww-perl/URI/commit/956619a9e94f86d8d2c529b4e06a3674c54a73e7.patch"
        },
        {
          "tags": [
            "issue-tracking"
          ],
          "url": "https://github.com/libwww-perl/URI/pull/191"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/OALDERS/URI-5.36/changes"
        },
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://www.rfc-editor.org/rfc/rfc5891#section-5.2"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to URI 5.36 or later."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "URI versions before 5.36 for Perl encode non-NFC host names to non-standard punycode labels via missing normalization in nameprep",
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-19953",
    "datePublished": "2026-08-31T17:29:42.929Z",
    "dateReserved": "2026-08-15T21:13:08.480Z",
    "dateUpdated": "2026-08-31T20:07:50.422Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Detection rules are retrieved from Rulezet.

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.

Action not permitted

ubuntu-cve-2026-19953

Vulnerability from osv_ubuntu

CVE-2026-19953 (GCVE-0-2026-19953)

Tags

Sightings

Nomenclature