CVE-2019-6338
HIGHCVE-2019-6338 is a high-severity (CVSS 8) Deserialization of Untrusted Data vulnerability in drupal/drupal. O3 Security confirms whether CVE-2019-6338 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Drupal core third-party PEAR Archive_Tar library is vulnerable to Deserialization of Untrusted Data
Real-World Exposure
drupal/drupal🐘drupal/drupal🐘drupal/drupalReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
In Drupal Core versions 7.x prior to 7.62, 8.6.x prior to 8.6.6 and 8.5.x prior to 8.5.9; Drupal core uses the third-party PEAR Archive_Tar library. This library has released a security update which impacts some Drupal configurations. Refer to CVE-2018-1000888 for details
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | drupal/drupal | ≥ 7.0.0&&< 7.62.0 | 7.62.0 |
| 🐘Packagist | drupal/drupal | ≥ 8.0.0&&< 8.5.9 | 8.5.9 |
| 🐘Packagist | drupal/drupal | ≥ 8.6.0&&< 8.6.6 | 8.6.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for drupal/drupal. 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 drupal/drupal to 7.62.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-6338 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-2019-6338 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-2019-6338. 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-2019-6338 in your dependencies?
O3 detects CVE-2019-6338 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.