CVE-2026-85396

high

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.

References

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

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

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

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

https://github.com/rubyzip/rubyzip

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

Details

Source: Mitre, NVD

Published: 2026-09-03

Updated: 2026-09-03

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:N

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Severity: High

CVSS v4

Base Score: 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

Severity: High

EPSS

EPSS: 0.00383