CVE-2016-5772: Double free vulnerability in the php_wddx_process_data function in wddx.c in the WDDX extension in PHP before

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CRITICAL 9.8REMOTEWATCHLISTUPGRADEDOWNGRADEMITIGATE

CVE-2016-5772 is a critical-severity flaw (CVSS 9.8) affecting php, linux enterprise debuginfo, leap. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Double free vulnerability in the php_wddx_process_data function in wddx.c in the WDDX extension in PHP before 5.5.37, 5.6.x before 5.6.23, and 7.x before 7.0.8 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via crafted XML data that is mishandled in a wddx_deserialize call.

Why this priority

Critical severity
EPSS top 5%: 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	9.7% (top 5%)
CISA exploited list	No
Weakness	CWE-415
Published	2016-08-07
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: opensuse · php · suse

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

Am I affected?

Timeline

2016-08-07 10:59 UTCPublished CVE record published
2026-06-17 00:50 UTCUpdated Record last modified

php php UPGRADE

Affected: < 5.5.37 · >= 5.6.0 and < 5.6.23 · >= 7.0.0 and < 7.0.8

Fixed in: 5.5.37, 5.6.23, 7.0.8

Safe to downgrade to: a release before 5.6.0

1. Check installed version

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

2. UPGRADE to 5.5.37 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade php

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 5.6.0 (Debian / Ubuntu)

apt-cache madison php sudo apt install php=<VERSION_BEFORE_5.6.0> sudo apt-mark hold php

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

dnf --showduplicates list php sudo dnf downgrade php-<VERSION_BEFORE_5.6.0> sudo dnf versionlock add php

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.

suse linux enterprise debuginfo DOWNGRADE

Affected: 11 sp4

Fixed in: no fixed release known

Safe to downgrade to: a release before 11

1. Check installed version

apt-cache policy linux-enterprise-debuginfo || rpm -q linux-enterprise-debuginfo || linux-enterprise-debuginfo --version

2. No fixed release: DOWNGRADE to a release before 11 (Debian / Ubuntu)

apt-cache madison linux-enterprise-debuginfo sudo apt install linux-enterprise-debuginfo=<VERSION_BEFORE_11> sudo apt-mark hold linux-enterprise-debuginfo

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

dnf --showduplicates list linux-enterprise-debuginfo sudo dnf downgrade linux-enterprise-debuginfo-<VERSION_BEFORE_11> sudo dnf versionlock add linux-enterprise-debuginfo

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.

opensuse leap MITIGATE

Affected: 42.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 42.1

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.

opensuse opensuse MITIGATE

Affected: 13.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 13.2

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.

suse linux enterprise server MITIGATE

Affected: 11 sp4

Fixed in: no fixed release known

Safe to downgrade to: a release before 11

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.

suse linux enterprise software development kit MITIGATE

Affected: 11 sp4

Fixed in: no fixed release known

Safe to downgrade to: a release before 11

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 · rust-ingredients · FIXED · 0.3.3-2.fc46 · FEDORA-2026-0b3d9feffd · source

sudo dnf upgrade --advisory=FEDORA-2026-0b3d9feffd

Fedora ELN · dpkg · FIXED · 1.23.11-2.eln159 · FEDORA-2026-732e4ac21b · source

sudo dnf upgrade --advisory=FEDORA-2026-732e4ac21b

RHEL 5 · php · DEFERRED

RHEL 5 · php53 · DEFERRED

RHEL 6 · php · DEFERRED

RHEL 7 · php · DEFERRED

Amazon Linux 1 · see advisory · FIXED · ALAS-2016-728 · source

sudo yum update --advisory=ALAS-2016-728

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-2016-5772?

php: upgrade to 5.5.37, 5.6.23, 7.0.8; linux enterprise debuginfo: downgrade or apply the listed mitigation; leap: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2016-5772 being exploited?

CVE-2016-5772 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-2016-5772 affect?

CVE-2016-5772 affects php, linux enterprise debuginfo, leap. Severity is critical (CVSS 9.8). Double free vulnerability in the php_wddx_process_data function in wddx.c in the WDDX extension in PHP before 5.5.37, 5.6.x before 5.6.23, and 7.x before 7.0.8 allows remote attackers to cause a denial of service (application crash) or poss

How urgent is CVE-2016-5772?

Priority 73/100. Critical severity; EPSS top 5%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

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References

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