CVE-2026-85396
Publication date 4 September 2026
Last updated 4 September 2026
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| ruby-zip | 26.04 LTS resolute |
Needs evaluation
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
Severity score breakdown
CVSS version:
Base score
8.7 · High
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
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
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-85396
- https://github.com/rubyzip/rubyzip/issues/664
- https://github.com/geo-chen/oss/blob/main/rubyzip.md
- https://github.com/rubyzip/rubyzip
- https://github.com/rubyzip/rubyzip/blob/v3.3.1/lib/zip/entry.rb
- https://github.com/rubyzip/rubyzip/commit/17edfbf4423b83211b075acc23a7d8640da63449
- 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