rubyzip up to 3.3.x Path Validation Zip::Entry#extract path traversal

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k1.71-

Summaryinfo

A vulnerability has been found in rubyzip up to 3.3.x and classified as problematic. The affected element is the function Zip::Entry#extract of the component Path Validation. This manipulation causes path traversal. The identification of this vulnerability is CVE-2026-85396. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability has been found in rubyzip up to 3.3.x and classified as problematic. Affected by this vulnerability is the function Zip::Entry#extract of the component Path Validation. The manipulation with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-22. 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. As an impact it is known to affect integrity. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-85396 since 09/03/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1006 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 342729 (Linux Distros Unpatched Vulnerability : CVE-2026-85396), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.4.0 eliminates this vulnerability. Applying the patch 17edfbf4423b83211b075acc23a7d8640da63449 is able to eliminate this problem.

The vulnerability is also documented in the databases at Tenable (342729) and EUVD (EUVD-2026-70673). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (VulnCheck): 🔒

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Path traversal
CWE: CWE-22
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 342729
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-85396

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: rubyzip 3.4.0
Patch: 17edfbf4423b83211b075acc23a7d8640da63449

Timelineinfo

09/03/2026 Advisory disclosed
09/03/2026 +0 days CVE reserved
09/03/2026 +0 days VulDB entry created
09/04/2026 +1 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-85396 (🔒)
GCVE (CVE): GCVE-0-2026-85396
GCVE (VulDB): GCVE-100-398569
EUVD: 🔒

Entryinfo

Created: 09/03/2026 21:12
Updated: 09/04/2026 11:58
Changes: 09/03/2026 21:12 (78), 09/03/2026 22:21 (1), 09/04/2026 11:58 (2)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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