CVE-2026-40491
MEDIUMCVE-2026-40491 is a medium-severity (CVSS 6.5) remote code execution vulnerability in gdown. O3 Security confirms whether CVE-2026-40491 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
gdown Affected by Arbitrary File Write via Path Traversal in gdown.extractall
Blast Radius
gdownReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
gdown is a Google Drive public file/folder downloader. Versions prior to 5.2.2 are vulnerable to a Path Traversal attack within the extractall functionality. When extracting a maliciously crafted ZIP or TAR archive, the library fails to sanitize or validate the filenames of the archive members. This allow files to be written outside the intended destination directory, potentially leading to arbitrary file overwrite and Remote Code Execution (RCE). Version 5.2.2 contains a fix.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | gdown | all versions | 5.2.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gdown. 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 gdown to 5.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40491 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-2026-40491 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-2026-40491. 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-2026-40491 in your dependencies?
O3 detects CVE-2026-40491 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.