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.
CVE-2026-82455
HIGHPre-NVD 7.17.1—Trending — 3 sources updated this week
EchelonGraph scoreHIGH confidence
Score 7.1 from GitHub Security Advisory published 2026-08-29. a secondary CVSS source baseline 7.1; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
7.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 7.1Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.1
- EG Score
- 7.1(high)
- EG Risk
- 36(Track)EG Risk 36/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity71% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
Published
August 29, 2026
Last Modified
August 29, 2026
Advisory Details (4)
Auto-updated Aug 29, 2026Upstream fix merged — awaiting tagged release. Sources: github_pr, github_commit.
generic
RubyGems before 4.0.13 Path Traversal via Symlink Resolution | Advisories | VulnCheck
https://www.vulncheck.com/advisories/rubygems-before-4.0.13-path-traversal-via-symlink-resolutiongeneric
GitHub - ruby/rubygems: Library packaging and distribution for Ruby. · GitHub
https://github.com/ruby/rubygemsgithub_commit
commit 103ca4230dea (ruby/rubygems)
Fix landed in ruby/rubygems commit 103ca4230dea — awaiting tagged release
https://github.com/ruby/rubygems/commit/103ca4230deacb31b9fcd813de109e83b5fc71acgithub_pr
Prevent extraction from escaping destination_dir via pre-existing symlinks
Fix merged in ruby/rubygems PR #9493 on 2026-05-26 — awaiting tagged release
https://github.com/ruby/rubygems/pull/9493Vendor Advisories for CVE-2026-82455(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 5× in last 7d / 5× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-30 01:25 UTCEG score recompute
- 2026-08-30 01:25 UTCGHSA enrichment
- 2026-08-29 14:23 UTCEG score recompute
- 2026-08-29 13:53 UTCEG score recompute
- 2026-08-29 13:52 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(4)
What is CVE-2026-82455?
CVE-2026-82455 is a high vulnerability published on August 29, 2026. 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…
When was CVE-2026-82455 disclosed?
CVE-2026-82455 was first published in the National Vulnerability Database on August 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-82455?
CVE-2026-82455 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2026-82455?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-82455, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-82455
Is Your Infrastructure Affected by CVE-2026-82455?
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