CVE-2016-3427: Oracle Java SE and JRockit Unspecified Vulnerability

Patch now

CRITICAL 9.8EXPLOITEDREMOTEWATCHLISTDOWNGRADEDOWNGRADEDOWNGRADE

CVE-2016-3427 is a critical-severity flaw (CVSS 9.8) affecting jdk, jre, jrockit, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Unspecified vulnerability in Oracle Java SE 6u113, 7u99, and 8u77; Java SE Embedded 8u77; and JRockit R28.3.9 allows remote attackers to affect confidentiality, integrity, and availability via vectors related to JMX.

Why this priority

Critical severity
EPSS top 1%: very likely to be exploited
Exploited in the wild (CISA KEV)
CISA SSVC: automatable with total technical impact
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	92.3% (top 1%)
CISA exploited list	Yes, fix due 2023-06-02
Weakness	CWE-284
Published	2016-04-21
Last modified	2026-06-17

Publisher (CNA): Oracle · Vendor: canonical · debian · oracle

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

Am I affected?

Timeline

2016-04-21 11:00 UTCPublished CVE record published
2023-05-12Exploited Added to the CISA Known Exploited Vulnerabilities list
2023-06-02Deadline CISA due date for US federal agencies to patch
2026-06-17 00:45 UTCUpdated Record last modified

oracle jdk DOWNGRADE

Affected: 1.6.0 update113 · 1.7.0 update99 · 1.8.0 update77

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.6.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.6.0 (Debian / Ubuntu)

apt-cache madison jdk sudo apt install jdk=<VERSION_BEFORE_1.6.0> sudo apt-mark hold jdk

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list jdk sudo dnf downgrade jdk-<VERSION_BEFORE_1.6.0> sudo dnf versionlock add jdk

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.

oracle jre DOWNGRADE

Affected: 1.6.0 update113 · 1.7.0 update99 · 1.8.0 update77

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.6.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.6.0 (Debian / Ubuntu)

apt-cache madison jre sudo apt install jre=<VERSION_BEFORE_1.6.0> sudo apt-mark hold jre

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list jre sudo dnf downgrade jre-<VERSION_BEFORE_1.6.0> sudo dnf versionlock add jre

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.

oracle jrockit DOWNGRADE

Affected: r28.3.9

Fixed in: no fixed release known

Safe to downgrade to: a release before r28.3.9

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before r28.3.9 (Debian / Ubuntu)

apt-cache madison jrockit sudo apt install jrockit=<VERSION_BEFORE_r28.3.9> sudo apt-mark hold jrockit

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list jrockit sudo dnf downgrade jrockit-<VERSION_BEFORE_r28.3.9> sudo dnf versionlock add jrockit

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.

oracle linux MITIGATE

Affected: 5 · 6 · 7

Fixed in: no fixed release known

Safe to downgrade to: a release before 5

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.

canonical ubuntu linux MITIGATE

Affected: 12.04 · 14.04 · 15.10 · 16.04

Fixed in: no fixed release known

Safe to downgrade to: a release before 12.04

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.

debian debian linux MITIGATE

Affected: 8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · perl-Net-IDN-Encode · FIXED · 2.600-1.fc46 · FEDORA-2026-84eff0ea64 · source

sudo dnf upgrade --advisory=FEDORA-2026-84eff0ea64

Fedora ELN · libXISF · FIXED · 0.2.15-2.eln159 · FEDORA-2026-b9e2d1bda0 · source

sudo dnf upgrade --advisory=FEDORA-2026-b9e2d1bda0

RHEL 5 · java-1.7.0-openjdk · FIXED · java-1.7.0-openjdk-1.7.0.101-2.6.6.1.el5_11

sudo dnf upgrade --advisory=RHSA-2016:0676 rpm -q java-1.7.0-openjdk

RHEL 5 · java-1.6.0-openjdk · FIXED · java-1.6.0-openjdk-1.6.0.39-1.13.11.0.el5_11

sudo dnf upgrade --advisory=RHSA-2016:0723 rpm -q java-1.6.0-openjdk

RHEL 5 Supplementary · java-1.7.0-ibm · FIXED · java-1.7.0-ibm-1.7.0.9.40-1jpp.1.el5

sudo dnf upgrade --advisory=RHSA-2016:0702 rpm -q java-1.7.0-ibm

RHEL 5 Supplementary · java-1.6.0-ibm · FIXED · java-1.6.0-ibm-1.6.0.16.25-1jpp.1.el5

sudo dnf upgrade --advisory=RHSA-2016:0708 rpm -q java-1.6.0-ibm

RHEL 6 · java-1.8.0-openjdk · FIXED · java-1.8.0-openjdk-1.8.0.91-0.b14.el6_7

sudo dnf upgrade --advisory=RHSA-2016:0651 rpm -q java-1.8.0-openjdk

Amazon Linux 1 · see advisory · FIXED · ALAS-2016-700 · source

sudo yum update --advisory=ALAS-2016-700

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: kc.mcafee.com/corporate/index?page=content&id=SB10159

Verify at the official source NVD · CVE Program · CISA KEV catalog · 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-2016-3427?

jdk: downgrade or apply the listed mitigation; jre: downgrade or apply the listed mitigation; jrockit: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2016-3427 being exploited?

Yes. CVE-2016-3427 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2016-3427 affect?

CVE-2016-3427 affects jdk, jre, jrockit. Severity is critical (CVSS 9.8). Unspecified vulnerability in Oracle Java SE 6u113, 7u99, and 8u77; Java SE Embedded 8u77; and JRockit R28.3.9 allows remote attackers to affect confidentiality, integrity, and availability via vectors related to JMX.

How urgent is CVE-2016-3427?

Priority 97/100. Critical severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Java vulnerabilities · Ubuntu vulnerabilities · Debian vulnerabilities

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References

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