CVE-2016-6662: Oracle MySQL through 5.5.52, 5.6.x through 5.6.33, and 5.7.x through 5.7.15; MariaDB before 5.5.51, 10.0.x bef

This week

CRITICAL 9.8REMOTEWATCHLISTUPGRADEUPGRADEUPGRADE

CVE-2016-6662 is a critical-severity flaw (CVSS 9.8) affecting mysql, percona server, mariadb. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Oracle MySQL through 5.5.52, 5.6.x through 5.6.33, and 5.7.x through 5.7.15; MariaDB before 5.5.51, 10.0.x before 10.0.27, and 10.1.x before 10.1.17; and Percona Server before 5.5.51-38.1, 5.6.x before 5.6.32-78.0, and 5.7.x before 5.7.14-7 allow local users to create arbitrary configurations and bypass certain protection mechanisms by setting general_log_file to a my.cnf configuration. NOTE: this can be leveraged to execute arbitrary code with r

Why this priority

Critical severity
EPSS top 1%: very likely to be exploited
Public exploit reference
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	67.7% (top 1%)
CISA exploited list	No
Weakness	CWE-264
Published	2016-09-20
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: debian · mariadb · oracle · percona · redhat

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

Am I affected?

Timeline

2016-09-20 18:59 UTCPublished CVE record published
2026-06-17 00:51 UTCUpdated Record last modified

oracle mysql UPGRADE

Affected: >= 5.5.0 and <= 5.5.52 · >= 5.6.0 and <= 5.6.33 · >= 5.7.0 and <= 5.7.15

Fixed in: newer than 5.7.15

Safe to downgrade to: a release before 5.5.0

1. Check installed version

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

2. UPGRADE to newer than 5.7.15 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mysql

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 5.5.0 (Debian / Ubuntu)

apt-cache madison mysql sudo apt install mysql=<VERSION_BEFORE_5.5.0> sudo apt-mark hold mysql

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

dnf --showduplicates list mysql sudo dnf downgrade mysql-<VERSION_BEFORE_5.5.0> sudo dnf versionlock add mysql

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.

percona percona server UPGRADE

Affected: >= 5.5 and < 5.5.51-38.1 · >= 5.6 and < 5.6.32-78.0 · >= 5.7 and < 5.7.14-7

Fixed in: 5.5.51-38.1, 5.6.32-78.0, 5.7.14-7

Safe to downgrade to: a release before 5.5

1. Check installed version

apt-cache policy percona-server || rpm -q percona-server || percona-server --version

2. UPGRADE to 5.5.51-38.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade percona-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade percona-server

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 5.5 (Debian / Ubuntu)

apt-cache madison percona-server sudo apt install percona-server=<VERSION_BEFORE_5.5> sudo apt-mark hold percona-server

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

dnf --showduplicates list percona-server sudo dnf downgrade percona-server-<VERSION_BEFORE_5.5> sudo dnf versionlock add percona-server

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.

mariadb mariadb UPGRADE

Affected: >= 5.5.20 and < 5.5.51 · >= 10.0.0 and < 10.0.27 · >= 10.1.0 and < 10.1.17

Fixed in: 5.5.51, 10.0.27, 10.1.17

Safe to downgrade to: a release before 5.5.20

1. Check installed version

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

2. UPGRADE to 5.5.51 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mariadb

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 5.5.20 (Debian / Ubuntu)

apt-cache madison mariadb sudo apt install mariadb=<VERSION_BEFORE_5.5.20> sudo apt-mark hold mariadb

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

dnf --showduplicates list mariadb sudo dnf downgrade mariadb-<VERSION_BEFORE_5.5.20> sudo dnf versionlock add mariadb

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.

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.

redhat openstack DOWNGRADE

Affected: 5.0 · 6.0 · 7.0 · 8 · 9

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 5.0 (Debian / Ubuntu)

apt-cache madison openstack sudo apt install openstack=<VERSION_BEFORE_5.0> sudo apt-mark hold openstack

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

dnf --showduplicates list openstack sudo dnf downgrade openstack-<VERSION_BEFORE_5.0> sudo dnf versionlock add openstack

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 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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · perl-Spreadsheet-XLSX · FIXED · 0.20-1.fc46 · FEDORA-2026-064736b436 · source

sudo dnf upgrade --advisory=FEDORA-2026-064736b436

Fedora ELN · bitcoin-core · FIXED · 32.1-2.eln159 · FEDORA-2026-41e13beebe · source

sudo dnf upgrade --advisory=FEDORA-2026-41e13beebe

Ubuntu 22.04 · mysql-8.0 · NOT AFFECTED

Ubuntu 20.04 · mysql-8.0 · NOT AFFECTED

Ubuntu 24.04 · mysql-8.0 · NOT AFFECTED

Ubuntu 24.10 · mysql-8.0 · NOT AFFECTED

RHEL 6 · mysql · FIXED · mysql-5.1.73-8.el6_8

sudo dnf upgrade --advisory=RHSA-2017:0184 rpm -q mysql

RHEL 7 · mariadb · FIXED · mariadb-5.5.52-1.el7

sudo dnf upgrade --advisory=RHSA-2016:2595 rpm -q mariadb

RHEL OpenStack Platform 5.0 (Icehouse) for RHEL 6 · mariadb-galera · FIXED · mariadb-galera-5.5.42-1.1.el6ost

sudo dnf upgrade --advisory=RHSA-2016:2058 rpm -q mariadb-galera

RHEL OpenStack Platform 5.0 (Icehouse) for RHEL 7 · mariadb-galera · FIXED · mariadb-galera-5.5.42-1.2.el7ost

sudo dnf upgrade --advisory=RHSA-2016:2059 rpm -q mariadb-galera

RHEL OpenStack Platform 6.0 (Juno) for RHEL 7 · mariadb-galera · FIXED · mariadb-galera-5.5.42-1.2.el7ost

sudo dnf upgrade --advisory=RHSA-2016:2060 rpm -q mariadb-galera

Amazon Linux 1 · see advisory · FIXED · ALAS-2017-800 · source

sudo yum update --advisory=ALAS-2017-800

Public exploits and detection

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

GitHub PoC: MAYASEVEN/CVE-2016-6662 (28 stars)
GitHub PoC: Ashrafdev/MySQL-Remote-Root-Code-Execution (9 stars)
GitHub PoC: meersjo/ansible-mysql-cve-2016-6662 (1 stars)
Write-up: www.exploit-db.com/exploits/40360/
Write-up: www.percona.com/blog/2016/09/12/percona-server-critical-update-cve-2016-6662/
GitHub PoC: KosukeShimofuji/CVE-2016-6662
Exploit-DB: MySQL / MariaDB / PerconaDB 5.5.51/5.6.32/5.7.14 - Code Execution / Privilege Escalation

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-2016-6662?

mysql: upgrade to newer than 5.7.15; percona server: upgrade to 5.5.51-38.1, 5.6.32-78.0, 5.7.14-7; mariadb: upgrade to 5.5.51, 10.0.27, 10.1.17. Exact commands for each OS are on this page.

Is CVE-2016-6662 being exploited?

CVE-2016-6662 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-2016-6662 affect?

CVE-2016-6662 affects mysql, percona server, mariadb. Severity is critical (CVSS 9.8). Oracle MySQL through 5.5.52, 5.6.x through 5.6.33, and 5.7.x through 5.7.15; MariaDB before 5.5.51, 10.0.x before 10.0.27, and 10.1.x before 10.1.17; and Percona Server before 5.5.51-38.1, 5.6.x before 5.6.32-78.0, and 5.7.x before 5.7.14-7

How urgent is CVE-2016-6662?

Priority 74/100. Critical severity; EPSS top 1%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

MySQL vulnerabilities · MariaDB vulnerabilities · Debian vulnerabilities · OpenStack vulnerabilities

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References

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