# CVE-2026-82455

## Summary

- **CVE ID:** CVE-2026-82455
- **Severity:** MEDIUM
- **CVSS Score:** 7.1 (CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N)
- **CWE:** CWE-59
- **Published:** Aug 29, 2026
- **Last Modified:** Aug 31, 2026

## Description

RubyGems fails to re-validate path containment after filesystem symlink resolution during gem extraction. When a pre-existing symlink inside the destination directory points outside the extraction root, extracted files that appear to be written under the destination directory can instead be written outside of it, breaking the extraction safety boundary. The fix resolves the real path of the parent directory before writing and raises Gem::Package::PathError if it escapes the destination directory.

## Affected Products

- ruby — rubygems (3.2.30)

## References

- [CNA](https://github.com/ruby/rubygems/pull/9493)
- [CNA](https://github.com/ruby/rubygems/commit/103ca4230deacb31b9fcd813de109e83b5fc71ac)
- [CNA](https://github.com/ruby/rubygems)
- [CNA](https://www.vulncheck.com/advisories/rubygems-before-4.0.13-path-traversal-via-symlink-resolution)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.14%
- **EPSS Percentile:** 4.0

---
_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._