CVE-2025-48387
CVE-2025-48387 is a Path Traversal vulnerability in tar-fs. O3 Security confirms whether CVE-2025-48387 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
tar-fs has issue where extract can write outside the specified dir with a specific tarball
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
tar-fsnpmDescription
tar-fs provides filesystem bindings for tar-stream. Versions prior to 3.0.9, 2.1.3, and 1.16.5 have an issue where an extract can write outside the specified dir with a specific tarball. This has been patched in versions 3.0.9, 2.1.3, and 1.16.5. As a workaround, use the ignore option to ignore non files/directories.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | tar-fs | all versions | 1.16.5 |
| 📦npm | tar-fs | ≥ 2.0.0&&< 2.1.3 | 2.1.3 |
| 📦npm | tar-fs | ≥ 3.0.0&&< 3.0.9 | 3.0.9 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tar-fs. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update tar-fs to 1.16.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-48387 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-48387 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-48387. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-48387 in your dependencies?
O3 detects CVE-2025-48387 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.