CVE-2026-85396

Published: Sep 3, 2026Modified: Sep 3, 2026

8.7

Vector

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XShow less

Source: disclosure@vulncheck.com (Secondary)

Description

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.

Related CWEs

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.

References (6)

https://github.com/geo-chen/oss/blob/main/rubyzip.md

Source: disclosure@vulncheck.com

https://github.com/rubyzip/rubyzip

Source: disclosure@vulncheck.com

https://github.com/rubyzip/rubyzip/blob/v3.3.1/lib/zip/entry.rb

Source: disclosure@vulncheck.com

https://github.com/rubyzip/rubyzip/commit/17edfbf4423b83211b075acc23a7d8640da63449

Source: disclosure@vulncheck.com

https://github.com/rubyzip/rubyzip/releases/tag/v3.4.0

Source: disclosure@vulncheck.com

https://www.vulncheck.com/advisories/rubyzip-before-3.4.0-path-traversal-in-zip-entry-extract-via-sibling-directory-prefix

Source: disclosure@vulncheck.com

Timeline

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