CVE-2020-5280 is a high-severity (CVSS 7.5) CWE-23 vulnerability in org.http4s:http4s-server_2.12. O3 Security confirms whether CVE-2020-5280 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Local file inclusion vulnerability in http4s
Real-World Exposure
org.http4s:http4s-server_2.12☕org.http4s:http4s-server_2.12☕org.http4s:http4s-server_2.12Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
http4s before versions 0.18.26, 0.20.20, and 0.21.2 has a local file inclusion vulnerability. This vulnerability applies to all users of org.http4s.server.staticcontent.FileService, org.http4s.server.staticcontent.ResourceService and org.http4s.server.staticcontent.WebjarService. URI normalization is applied incorrectly. Requests whose path info contain ../ or // can expose resources outside of the configured location. This issue is patched in versions 0.18.26, 0.20.20, and 0.21.2. Note that 0.19.0 is a deprecated release and has never been supported.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.http4s:http4s-server_2.12 | all versions | 0.18.26 |
| ☕Maven | org.http4s:http4s-server_2.12 | ≥ 0.19.0&&< 0.20.20 | 0.20.20 |
| ☕Maven | org.http4s:http4s-server_2.12 | ≥ 0.21.0&&< 0.21.2 | 0.21.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.http4s:http4s-server_2.12. 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 org.http4s:http4s-server_2.12 to 0.18.26 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-5280 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-2020-5280 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-2020-5280. 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-2020-5280 in your dependencies?
O3 detects CVE-2020-5280 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.