Vulnerability-Lookup

UBUNTU-CVE-2026-93712 (CVE-2026-93712)

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

Details

Dancer2 versions from 2.1.0 before 2.2.0 for Perl serve files from outside public_dir via relative path segments in the File route handler. The handler joins the request path onto public_dir without collapsing relative segments, and checks only that the result is a readable regular file. A request for /../outside.txt escapes public_dir, and percent-encoding the dots reaches the same file. The handler is off by default. An application is affected once it names File in route_handlers and sets static_handler to 0, which otherwise refuses a dot segment before the route runs. Any file the worker process can read is served to an unauthenticated request, including the application's config.yml above public_dir.

Severity

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-93712	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-93712	REPORT
	https://lists.security.metacpan.org/cve-announce/…	REPORT
	https://github.com/PerlDancer/Dancer2/security/ad…	REPORT
	https://github.com/PerlDancer/Dancer2/commit/2446…	REPORT
	https://metacpan.org/release/CROMEDOME/Dancer2-2.…	REPORT
	http://www.openwall.com/lists/oss-security/2026/09/22/4	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libdancer2-perl",
            "binary_version": "0.166001+dfsg-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "libdancer2-perl",
        "purl": "pkg:deb/ubuntu/libdancer2-perl@0.166001+dfsg-1?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.160003+dfsg-1",
        "0.163000+dfsg-1",
        "0.166001+dfsg-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libdancer2-perl",
            "binary_version": "0.205002+dfsg-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "libdancer2-perl",
        "purl": "pkg:deb/ubuntu/libdancer2-perl@0.205002+dfsg-2?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.205000+dfsg-1",
        "0.205002+dfsg-1",
        "0.205002+dfsg-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libdancer2-perl",
            "binary_version": "0.300000+dfsg-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "libdancer2-perl",
        "purl": "pkg:deb/ubuntu/libdancer2-perl@0.300000+dfsg-1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.208001+dfsg-1",
        "0.208002+dfsg-1",
        "0.300000+dfsg-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libdancer2-perl",
            "binary_version": "0.301004+dfsg-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "libdancer2-perl",
        "purl": "pkg:deb/ubuntu/libdancer2-perl@0.301004+dfsg-1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.300005+dfsg-1",
        "0.301004+dfsg-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libdancer2-perl",
            "binary_version": "1.1.0+dfsg-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "libdancer2-perl",
        "purl": "pkg:deb/ubuntu/libdancer2-perl@1.1.0+dfsg-1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.400001+dfsg-1",
        "1.0.0+dfsg-1",
        "1.1.0+dfsg-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libdancer2-perl",
            "binary_version": "1.1.2+dfsg-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "libdancer2-perl",
        "purl": "pkg:deb/ubuntu/libdancer2-perl@1.1.2+dfsg-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.1.2+dfsg-1"
      ]
    }
  ],
  "aliases": [],
  "details": "Dancer2 versions from 2.1.0 before 2.2.0 for Perl serve files from outside public_dir via relative path segments in the File route handler. The handler joins the request path onto public_dir without collapsing relative segments, and checks only that the result is a readable regular file. A request for `/../outside.txt` escapes public_dir, and percent-encoding the dots reaches the same file. The handler is off by default. An application is affected once it names File in route_handlers and sets static_handler to 0, which otherwise refuses a dot segment before the route runs. Any file the worker process can read is served to an unauthenticated request, including the application\u0027s config.yml above public_dir.",
  "id": "UBUNTU-CVE-2026-93712",
  "modified": "2026-09-22T00:00:00Z",
  "published": "2026-09-22T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-93712"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-93712"
    },
    {
      "type": "REPORT",
      "url": "https://lists.security.metacpan.org/cve-announce/msg/43742973/"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/PerlDancer/Dancer2/security/advisories/GHSA-6xw8-v24c-m783"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/PerlDancer/Dancer2/commit/2446a09ffb83fef71cc75c327bd6e4b1f007b885.patch"
    },
    {
      "type": "REPORT",
      "url": "https://metacpan.org/release/CROMEDOME/Dancer2-2.2.0/changes"
    },
    {
      "type": "REPORT",
      "url": "http://www.openwall.com/lists/oss-security/2026/09/22/4"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-93712"
  ]
}

CVE-2026-93712 (GCVE-0-2026-93712)

Vulnerability from cvelistv5 – Published: 2026-09-22 00:52 – Updated: 2026-09-22 19:19

Title

Dancer2 versions from 2.1.0 before 2.2.0 for Perl serve files from outside public_dir via relative path segments in the File route handler

Summary

Dancer2 versions from 2.1.0 before 2.2.0 for Perl serve files from outside public_dir via relative path segments in the File route handler. The handler joins the request path onto public_dir without collapsing relative segments, and checks only that the result is a readable regular file. A request for `/../outside.txt` escapes public_dir, and percent-encoding the dots reaches the same file. The handler is off by default. An application is affected once it names File in route_handlers and sets static_handler to 0, which otherwise refuses a dot segment before the route runs. Any file the worker process can read is served to an unauthenticated request, including the application's config.yml above public_dir.

Severity

7.5 (High)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-22 19:19 UTC

CWE

CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Assigner

CPANSec redhat root

References

4 references

URL	Tags
https://github.com/PerlDancer/Dancer2/security/ad…	vendor-advisory
https://github.com/PerlDancer/Dancer2/commit/2446…	patch
https://metacpan.org/release/CROMEDOME/Dancer2-2.…	release-notes
http://www.openwall.com/lists/oss-security/2026/09/22/4

Impacted products

1 product

Vendor	Product	Version
		Affected: 2.1.0 , < 2.2.0 (custom)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-09-22T02:09:48.478Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/09/22/4"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-93712",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-22T19:19:41.602914Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-22T19:19:59.077Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Dancer2"
          ],
          "packageName": "Dancer2",
          "packageURL": "pkg:cpan/Dancer2",
          "programFiles": [
            "lib/Dancer2/Handler/File.pm"
          ],
          "programRoutines": [
            {
              "name": "Dancer2::Handler::File::code"
            }
          ],
          "repo": "https://github.com/PerlDancer/Dancer2",
          "versions": [
            {
              "lessThan": "2.2.0",
              "status": "affected",
              "version": "2.1.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Dancer2 versions from 2.1.0 before 2.2.0 for Perl serve files from outside public_dir via relative path segments in the File route handler.\n\nThe handler joins the request path onto public_dir without collapsing relative segments, and checks only that the result is a readable regular file. A request for `/../outside.txt` escapes public_dir, and percent-encoding the dots reaches the same file.\n\nThe handler is off by default. An application is affected once it names File in route_handlers and sets static_handler to 0, which otherwise refuses a dot segment before the route runs.\n\nAny file the worker process can read is served to an unauthenticated request, including the application\u0027s config.yml above public_dir."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-22",
              "description": "CWE-22 Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-22T00:52:36.047Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/PerlDancer/Dancer2/security/advisories/GHSA-6xw8-v24c-m783"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/PerlDancer/Dancer2/commit/2446a09ffb83fef71cc75c327bd6e4b1f007b885.patch"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/CROMEDOME/Dancer2-2.2.0/changes"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to Dancer2 2.2.0 or later."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "timeline": [
        {
          "lang": "en",
          "time": "2026-09-16T00:00:00.000Z",
          "value": "Version 2.2.0 released with fix."
        }
      ],
      "title": "Dancer2 versions from 2.1.0 before 2.2.0 for Perl serve files from outside public_dir via relative path segments in the File route handler",
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-93712",
    "datePublished": "2026-09-22T00:52:36.047Z",
    "dateReserved": "2026-09-18T15:07:22.163Z",
    "dateUpdated": "2026-09-22T19:19:59.077Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Confirmed: The vulnerability has been validated from an analyst's perspective.
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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.
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UBUNTU-CVE-2026-93712 (CVE-2026-93712)

CVE-2026-93712 (GCVE-0-2026-93712)

Tags

Sightings

Nomenclature

Related by attack behaviour