Vulnerability-Lookup

ubuntu-cve-2026-85396

Vulnerability from osv_ubuntu

Published

2026-09-04 00:00

Modified

2026-09-04 00:00

Summary

Details

rubyzip versions before 3.4.0 contain a path traversal vulnerability in Zip::Entry#extract that fails to properly validate extraction paths using prefix comparison without trailing separators. Attackers can craft archive entries with names like ../upload_backup/owned.sh to write files outside the intended extraction directory into sibling paths sharing the destination prefix.

Severity

7.5 (High)


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

8.7 (High)


                    
                      CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-85396	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-85396	REPORT
	https://github.com/rubyzip/rubyzip/issues/664	REPORT
	https://github.com/geo-chen/oss/blob/main/rubyzip.md	REPORT
	https://github.com/rubyzip/rubyzip	REPORT
	https://github.com/rubyzip/rubyzip/blob/v3.3.1/li…	REPORT
	https://github.com/rubyzip/rubyzip/commit/17edfbf…	REPORT
	https://github.com/rubyzip/rubyzip/releases/tag/v3.4.0	REPORT
	https://www.vulncheck.com/advisories/rubyzip-befo…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-zip",
            "binary_version": "1.1.7-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "ruby-zip",
        "purl": "pkg:deb/ubuntu/ruby-zip@1.1.7-1?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.1.7-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-zip",
            "binary_version": "1.2.1-1.1~build0.18.04.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "ruby-zip",
        "purl": "pkg:deb/ubuntu/ruby-zip@1.2.1-1.1~build0.18.04.1?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.1-1",
        "1.2.1-1.1~build0.18.04.1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-zip",
            "binary_version": "2.0.0-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "ruby-zip",
        "purl": "pkg:deb/ubuntu/ruby-zip@2.0.0-2?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.2.2-1",
        "2.0.0-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-zip",
            "binary_version": "2.3.0-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "ruby-zip",
        "purl": "pkg:deb/ubuntu/ruby-zip@2.3.0-2?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.0.0-2",
        "2.3.0-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-zip",
            "binary_version": "2.3.2-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "ruby-zip",
        "purl": "pkg:deb/ubuntu/ruby-zip@2.3.2-1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.3.2-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-zip",
            "binary_version": "3.2.2-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "ruby-zip",
        "purl": "pkg:deb/ubuntu/ruby-zip@3.2.2-2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.3.2-1",
        "3.2.2-1",
        "3.2.2-2"
      ]
    }
  ],
  "aliases": [],
  "details": "rubyzip versions before 3.4.0 contain a path traversal vulnerability in Zip::Entry#extract that fails to properly validate extraction paths using prefix comparison without trailing separators. Attackers can craft archive entries with names like ../upload_backup/owned.sh to write files outside the intended extraction directory into sibling paths sharing the destination prefix.",
  "id": "UBUNTU-CVE-2026-85396",
  "modified": "2026-09-04T00:00:00Z",
  "published": "2026-09-04T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-85396"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-85396"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/rubyzip/rubyzip/issues/664"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/geo-chen/oss/blob/main/rubyzip.md"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/rubyzip/rubyzip"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/rubyzip/rubyzip/blob/v3.3.1/lib/zip/entry.rb"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/rubyzip/rubyzip/commit/17edfbf4423b83211b075acc23a7d8640da63449"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/rubyzip/rubyzip/releases/tag/v3.4.0"
    },
    {
      "type": "REPORT",
      "url": "https://www.vulncheck.com/advisories/rubyzip-before-3.4.0-path-traversal-in-zip-entry-extract-via-sibling-directory-prefix"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-85396"
  ]
}

CVE-2026-85396 (GCVE-0-2026-85396)

Vulnerability from cvelistv5 – Published: 2026-09-03 18:54 – Updated: 2026-09-03 19:00

Title

rubyzip before 3.4.0 Path Traversal in Zip::Entry#extract via Sibling-Directory Prefix

Summary

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

7.5 (High)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-03 18:59 UTC

CWE

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

Assigner

VulnCheck mitre root

References

6 references

URL	Tags
https://github.com/rubyzip/rubyzip/commit/17edfbf…	patch
https://github.com/rubyzip/rubyzip	product
https://github.com/rubyzip/rubyzip/releases/tag/v3.4.0	release-notes
https://github.com/rubyzip/rubyzip/blob/v3.3.1/li…	technical-description
https://github.com/geo-chen/oss/blob/main/rubyzip.md	technical-description
https://www.vulncheck.com/advisories/rubyzip-befo…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
rubyzip	rubyzip	Affected: 0 , < 3.4.0 (semver) Unaffected: 3.4.0 (semver) cpe:2.3:a:rubyzip_project:rubyzip::::::::

Date Public

2026-06-12 00:00

Credits

George Chen

Show details on NVD website

JSON

To clipboard

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  "containers": {
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      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-85396",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-03T18:59:39.190691Z",
                "version": "2.0.3"
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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.