CVE-2026-85396
rubyzip before 3.4.0 Path Traversal in Zip::Entry#extract via Sibling-Directory Prefix
- 8.7HighCVSS base score
- 0.56%Exploitation in 30 daysEPSS · top 53% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By VulnCheck
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulnCheckCNA (assigner) | 4.0 | High8.7 | 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 |
| VulnCheckCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVDNVD · Awaiting Analysis | 4.0 | High8.7 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.56% · top 53% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.7.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- RubyGemsrubyzipGHSA-47m2-wp7j-p9vc (opens in a new tab)
References
References6
- Patch Commit (opens in a new tab)patch
- https://github.com/rubyzip/rubyzip (opens in a new tab)product
- rubyzip v3.4.0 Release Notes (opens in a new tab)release-notes
- https://github.com/rubyzip/rubyzip/blob/v3.3.1/lib/zip/entry.rb (opens in a new tab)technical-description
- https://github.com/geo-chen/oss/blob/main/rubyzip.md (opens in a new tab)technical-description
- VulnCheck Advisory: rubyzip before 3.4.0 Path Traversal in Zip::Entry#extract via Sibling-Directory Prefix (opens in a new tab)third-party-advisory
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-70673 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-47m2-wp7j-p9vc (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-85396)Record last updated .