Vulnerabilities in pkg:gem/rubyzip

PACKAGE
Advisory Identifier: GHSA-47m2-wp7j-p9vc
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Advisory Summary

CVE-2026-85396 is a HIGH (CVSS 7.5) path traversal vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Rubyzip libraries in the RubyGems ecosystem. The issue involves rubyzip path traversal vulnerability. Remediation is available by upgrading affected packages to version 3.4.0.

5 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:gem/rubyzip

5 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:gem/rubyzip. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-47m2-wp7j-p9vc CVE-2026-85396 HIGH rubyzip path traversal vulnerability
GHSA-5m2v-hc64-56h6 CVE-2019-16892 MODERATE Rubyzip denial of service
GHSA-gcqq-w6gr-h9j9 CVE-2017-5946 CRITICAL Directory traversal vulnerability in RubyZip
GHSA-vqcq-mrmw-mcmg CVE-2018-1000544 CRITICAL Rubyzip gem contains a Directory Traversal vulnerability in zip file component
GHSA-3q5q-f79q-7hr2 - HIGH High severity vulnerability that affects rubyzip

CVE-2026-85396 at a Glance

CVE Identifier CVE-2026-85396
GHSA Identifier GHSA-47m2-wp7j-p9vc
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Rubyzip
Package Ecosystem RubyGems
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-85396

To remediate this vulnerability, upgrade all affected Rubyzip dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

rubyzip fixed: 3.4.0 
Upgrade rubyzip to 3.4.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for rubyzip

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-85396, inspect your project dependencies for Rubyzip:

inspect dependencies for rubyzip

Analyze the terminal output to locate any version of Rubyzip in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.4.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. In Rubyzip, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-85396 Affected Rubyzip Versions

1 component(s)
Fixed Versions:
3.4.0
Product / Package Ecosystem Affected Versions Fixed Version
rubyzip
gem/rubyzip
RubyGems
< 3.4.0
3.4.0

References

NVD — CVE-2026-85396 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-85396
Security Fix Commit FIX COMMIT
https://github.com/rubyzip/rubyzip/commit/17edfbf4423b83211b075acc23a7d8640da63449
Rubyzip Source Repository REPOSITORY
https://github.com/geo-chen/oss/blob/main/rubyzip.md
Rubyzip Source Repository REPOSITORY
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rubyzip/CVE-2026-85396.yml
Rubyzip Source Repository REPOSITORY
https://github.com/rubyzip/rubyzip
Rubyzip Source Repository REPOSITORY
https://github.com/rubyzip/rubyzip/blob/v3.3.1/lib/zip/entry.rb
Rubyzip Release RELEASE
https://github.com/rubyzip/rubyzip/releases/tag/v3.4.0
www.vulncheck.com/advisories/rubyzip-... WEB
https://www.vulncheck.com/advisories/rubyzip-before-3.4.0-path-traversal-in-zip-entry-extract-via-sibling-directory-prefix

Frequently Asked Questions

What is CVE-2026-85396?
CVE-2026-85396 is a security vulnerability in Rubyzip involving rubyzip path traversal vulnerability under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Rubyzip versions are affected?
Affected versions include releases prior to 3.4.0 across affected packages: rubyzip.
What version fixes CVE-2026-85396?
Upgrading to 3.4.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is rubyzip affected?
Yes, rubyzip is affected in releases prior to 3.4.0. Upgrade your dependency to 3.4.0 or later.
What is the CVSS score of CVE-2026-85396?
CVE-2026-85396 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with CVE-2026-85396?
CVE-2026-85396 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.).
How can I check RubyGems dependencies for CVE-2026-85396?
Run the dependency tree command: 'inspect dependencies for rubyzip'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-47m2-wp7j-p9vc",
  "modified" : "2026-09-25T19:25:52Z",
  "published" : "2026-09-03T21:31:16Z",
  "aliases" : [ "CVE-2026-85396" ],
  "summary" : "rubyzip path traversal vulnerability",
  "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" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
  }, {
    "type" : "CVSS_V4",
    "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "rubyzip"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.4.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-85396"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubyzip/rubyzip/commit/17edfbf4423b83211b075acc23a7d8640da63449"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/geo-chen/oss/blob/main/rubyzip.md"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rubyzip/CVE-2026-85396.yml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/rubyzip/rubyzip"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubyzip/rubyzip/blob/v3.3.1/lib/zip/entry.rb"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubyzip/rubyzip/releases/tag/v3.4.0"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/rubyzip-before-3.4.0-path-traversal-in-zip-entry-extract-via-sibling-directory-prefix"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-25T19:25:52Z",
    "nvd_published_at" : "2026-09-03T19:17:31Z"
  }
}