CVE-2026-85396

CVE-2026-85396

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.

Vulnerability class: Path Traversal (Directory Traversal)

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-85396?
CVE-2026-85396 is a high-severity vulnerability, classified under Path Traversal. CVSS score: 7.5/10. Published 2026-09-03.
How severe is CVE-2026-85396?
High severity. CVSS v3 base score is 7.5 out of 10.