How severe is CVE-2020-27218?

CVE-2020-27218 has a CVSS score of 4.8/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2020-27218?

CVE-2020-27218 affects the following packages: org.eclipse.jetty:jetty-server (Maven). Ecosystems affected: Maven.

How do I fix CVE-2020-27218?

Update org.eclipse.jetty:jetty-server to 9.4.35.v20201120 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-27218 is resolved across your whole dependency graph.

How do I detect CVE-2020-27218 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.eclipse.jetty:jetty-server. 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.

How do I mitigate CVE-2020-27218 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2020-27218?

O3 pinpoints whether CVE-2020-27218 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2020-27218 actively exploited in the wild?

Yes. There are 7 known exploit references for CVE-2020-27218, including 7 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What type of vulnerability is CVE-2020-27218?

CVE-2020-27218 is classified as CWE-226 (CWE-226). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2020-27218 published, and has it been updated?

CVE-2020-27218 was published on November 28, 2020 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

CVE-2020-27218

MEDIUM

Buffer not correctly recycled in Gzip Request inflation

Also known asBIT-kafka-2020-27218BIT-spark-2020-27218GHSA-86wm-rrjm-8wh8

Published

Nov 28, 2020

Updated

Jul 8, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

7 known

Blast Radius

1 pkg affected

☕org.eclipse.jetty:jetty-server

Real-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

In Eclipse Jetty version 9.4.0.RC0 to 9.4.34.v20201102, 10.0.0.alpha0 to 10.0.0.beta2, and 11.0.0.alpha0 to 11.0.0.beta2, if GZIP request body inflation is enabled and requests from different clients are multiplexed onto a single connection, and if an attacker can send a request with a body that is received entirely but not consumed by the application, then a subsequent request on the same connection will see that body prepended to its body. The attacker will not see any data but may inject data into the body of the subsequent request.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.eclipse.jetty:jetty-server`	≥ 9.4.0&&< 9.4.35.v20201120	9.4.35.v20201120

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.