CVE-2026-85396: Rubyzip

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

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 products

• Rubyzip Rubyzip: before 3.4.0 (fixed in 3.4.0)

Published 2026-09-03. Last modified 2026-09-24.