path traversal vulnerability in pre-3.4.0 rubyzip gem
Published: September 03, 2026
SECURITY IDENTIFIERS
- CVE: CVE-2026-85396 (NVD)
- GHSA: GHSA-47m2-wp7j-p9vc
GEM
SEVERITY
CVSS v3.x: 7.5 (High)
PATCHED VERSIONS
>= 3.4.0
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
- https://nvd.nist.gov/vuln/detail/CVE-2026-85396
- https://rubygems.org/gems/rubyzip/versions/3.4.0
- https://github.com/rubyzip/rubyzip/releases/tag/v3.4.0
- https://github.com/rubyzip/rubyzip/blob/v3.4.0/Changelog.md#340-2026-06-14
- https://github.com/rubyzip/rubyzip/commit/17edfbf4423b83211b075acc23a7d8640da63449
- https://github.com/rubyzip/rubyzip/blob/v3.3.1/lib/zip/entry.rb
- https://github.com/geo-chen/oss/blob/main/rubyzip.md
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-70673
- https://www.vulncheck.com/advisories/rubyzip-before-3.4.0-path-traversal-in-zip-entry-extract-via-sibling-directory-prefix
- https://github.com/advisories/GHSA-47m2-wp7j-p9vc