CVE-2016-6814: When an application with unsupported Codehaus versions of Groovy from 1.7.0 to 2.4.3, Apache Groovy 2.4.4 to 2

This week

CRITICAL 9.8REMOTEWATCHLISTUPGRADEMITIGATE

CVE-2016-6814 is a critical-severity flaw (CVSS 9.8) affecting groovy, enterprise linux server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

When an application with unsupported Codehaus versions of Groovy from 1.7.0 to 2.4.3, Apache Groovy 2.4.4 to 2.4.7 on classpath uses standard Java serialization mechanisms, e.g. to communicate between servers or to store local data, it was possible for an attacker to bake a special serialized object that will execute code directly when deserialized. All applications which rely on serialization and do not isolate the code which deserializes object

Why this priority

Critical severity
EPSS top 3%: very likely to be exploited
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	17.2% (top 3%)
CISA exploited list	No
Weakness	CWE-502
Published	2018-01-18
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: apache · redhat

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-01-18 18:29 UTCPublished CVE record published
2026-06-17 00:51 UTCUpdated Record last modified

apache groovy UPGRADE

Affected: >= 1.7.0 and <= 2.4.3 · >= 2.4.4 and <= 2.4.7

Fixed in: newer than 2.4.7

Safe to downgrade to: a release before 1.7.0

1. Check installed version

apt-cache policy groovy || rpm -q groovy || groovy --version

2. UPGRADE to newer than 2.4.7 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade groovy

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade groovy

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.7.0 (Debian / Ubuntu)

apt-cache madison groovy sudo apt install groovy=<VERSION_BEFORE_1.7.0> sudo apt-mark hold groovy

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list groovy sudo dnf downgrade groovy-<VERSION_BEFORE_1.7.0> sudo dnf versionlock add groovy

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

redhat enterprise linux server MITIGATE

Affected: 7.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2016-6814?

groovy: upgrade to newer than 2.4.7; enterprise linux server: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2016-6814 being exploited?

CVE-2016-6814 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2016-6814 affect?

CVE-2016-6814 affects groovy, enterprise linux server. Severity is critical (CVSS 9.8). When an application with unsupported Codehaus versions of Groovy from 1.7.0 to 2.4.3, Apache Groovy 2.4.4 to 2.4.7 on classpath uses standard Java serialization mechanisms, e.g. to communicate between servers or to store local data, it was

How urgent is CVE-2016-6814?

Priority 69/100. Critical severity; EPSS top 3%: very likely to be exploited; Remotely exploitable, no login, no user action; On your watchlist

Software pages

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References

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