CVE-2026-85396

EUVD-2026-70673
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.
Path Traversal
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
rubyzip_projectrubyzip
𝑥
< 3.4.0
CNA
Debian logo
Debian Releases
Debian Product
Codename
ruby-zip
bookworm
vulnerable
forky
3.5.0+dfsg-1
fixed
sid
3.5.0+dfsg-1
fixed
trixie
vulnerable
Common Weakness Enumeration
References
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