CVE-2026-85396CWE-22path-traversal

CVE-2026-85396

High · published September 3, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
46.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS v4.0
8.7 · 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
EPSS
0.00564 · 46.1th percentile
Weakness
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Published
2026-09-03T23:17Z
References (6)
https://github.com/geo-chen/oss/blob/main/rubyzip.md · [email protected]https://github.com/rubyzip/rubyzip · [email protected]https://github.com/rubyzip/rubyzip/blob/v3.3.1/lib/zip/entry.rb · [email protected]https://github.com/rubyzip/rubyzip/commit/17edfbf4423b83211b075acc23a7d8640da63449 · [email protected]https://github.com/rubyzip/rubyzip/releases/tag/v3.4.0 · [email protected]https://www.vulncheck.com/advisories/rubyzip-before-3.4.0-path-traversal-in-zip-entry-extract-via-sibling-directory-prefix · [email protected]
EPSS history
Timeline
  • 05 SEP 03:44Z
    EPSS moved — → 0%
    epss
  • 03 SEP 18:54Z
    rubyzip before 3.4.0 Path Traversal in Zip::Entry#extract via Sibling-Directory Prefix
    cvelistv5