CVE-2023-48311
HIGHCVE-2023-48311 is a high-severity (CVSS 8) Improper Input Validation vulnerability in dockerspawner. O3 Security confirms whether CVE-2023-48311 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Any image allowed by default
Blast Radius
dockerspawnerReal-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
dockerspawner is a tool to spawn JupyterHub single user servers in Docker containers. Users of JupyterHub deployments running DockerSpawner starting with 0.11.0 without specifying DockerSpawner.allowed_images configuration allow users to launch any pullable docker image, instead of restricting to only the single configured image, as intended. This issue has been addressed in commit 3ba4b665b which has been included in dockerspawner release version 13. Users are advised to upgrade. Users unable to upgrade should explicitly set DockerSpawner.allowed_images to a non-empty list containing only the default image will result in the intended default behavior.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | dockerspawner | ≥ 0.11.0&&< 13.0.0 | 13.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for dockerspawner. 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 dockerspawner to 13.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-48311 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-2023-48311 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-2023-48311. 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-2023-48311 in your dependencies?
O3 detects CVE-2023-48311 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.