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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

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

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

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 is the EPSS score for CVE-2020-27218?

CVE-2020-27218 has an EPSS (Exploit Prediction Scoring System) score of 8.3%, placing it in the 95th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

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 October 24, 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

Not in CISA KEV

MEDIUM severity

CVE-2020-27218 — jetty-server

MEDIUM

CVE-2020-27218 is a medium-severity (CVSS 4.8) CWE-226 vulnerability in org.eclipse.jetty:jetty-server. 7 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for org.eclipse.jetty:jetty-server — see the affected versions and patch details below.

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

Oct 24, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

7 known

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

8.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs95th percentile — riskier than 95% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

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

Impact

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 by not consumed by the application, then a subsequent request on the same connection will see that body prepended to it's body.

The attacker will not see any data, but may inject data into the body of the subsequent request

CVE score is 4.8 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

Workarounds

The problem can be worked around by either:

Disabling compressed request body inflation by GzipHandler.
By always fully consuming the request content before sending a response.
By adding a Connection: close to any response where the servlet does not fully consume request content.

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`org.eclipse.jetty:jetty-server:9.4.35.v20201120`

Affected Products

17 products · 27 configurations

Application

kafkaapache

1 version

2.7.0

Application

sparkapache

2 versions

2.4.83.0.3

debian linuxdebian

1 version

10.0

Application

jettyeclipse

≥ 9.4.0 && < 9.4.35

2 versions

10.0.011.0.0

Application

oncommand system managernetapp

≥ 3.0 && ≤ 3.1.3

range

Application

snap creator frameworknetapp

all

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.

In Eclipse Jetty version 9.4.0.RC0 to 9.4.34.v20201102, 10.0.0.alpha0 to…

lists.apache.orgNVDJul 2021

Report on lists.apache.org

lists.apache.orgNVDJul 2021

Report on lists.apache.org

lists.apache.orgNVDJul 2021

Report on lists.apache.org

lists.apache.orgNVDDec 2021

Report on lists.apache.org

lists.apache.orgNVDDec 2021

Report on lists.apache.org

lists.apache.orgNVDDec 2021

Report on lists.apache.org

lists.apache.orgNVDDec 2021

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.eclipse.jetty:jetty-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
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.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

In OpenShift Container Platform (OCP), the Hive/Presto/Hadoop components that comprise the OCP Metering stack, ship the vulnerable version of jetty. Since the release of OCP 4.6, the Metering product has been deprecated [1], hence the affected components are marked as wontfix. This may be fixed in the future. [1]…

Product	Fixed in	Advisory
Red Hat AMQ 7.8.1	see advisory	RHSA-2021:0417
Red Hat AMQ LTS 7.4.6	`jetty`	RHSA-2021:0329
Red Hat Fuse 7.10	`jetty`	RHSA-2021:5134
Red Hat Integration Camel Quarkus 2	see advisory	RHSA-2021:4767
Red Hat Migration Toolkit for Containers 1.4	`rhmtc/openshift-migration-controller-rhel8:v1.4.6-4`	RHBA-2021:2854
Red Hat OpenShift Container Platform 3.11	`jenkins-0:2.289.1.1624365627-1.el7`	RHSA-2021:2517
Red Hat OpenShift Container Platform 4.5	`jenkins-0:2.277.3.1623846768-1.el7`	RHSA-2021:2431
Red Hat OpenShift Container Platform 4.6	`jenkins-0:2.277.3.1623853726-1.el8`	RHSA-2021:2499

Frequently Asked Questions

### Impact 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 by not consumed by the application, then a subsequent request on the same connection will see that body prepended to it's body. The attacker will not see any data, but may inject data into the body of the subsequent request CVE score is [4.8 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L](https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L&version=3.1) ##

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