CVE-2026-85396

Impact

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.

Affected packages

Weakness classification

References

• NVD record
• CVE.org record
• GitHub advisory
• https://github.com/advisories/GHSA-47m2-wp7j-p9vc
• https://nvd.nist.gov/vuln/detail/CVE-2026-85396
• https://github.com/rubyzip/rubyzip/commit/17edfbf4423b83211b075acc23a7d8640da63449
• https://github.com/geo-chen/oss/blob/main/rubyzip.md
• https://github.com/rubyzip/rubyzip/blob/v3.3.1/lib/zip/entry.rb
• https://github.com/rubyzip/rubyzip/releases/tag/v3.4.0
• https://www.vulncheck.com/advisories/rubyzip-before-3.4.0-path-traversal-in-zip-entry-extract-via-sibling-directory-prefix
• https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rubyzip/CVE-2026-85396.yml
• https://github.com/rubyzip/rubyzip