CVE-2019-11043: PHP FastCGI Process Manager (FPM) Buffer Overflow Vulnerability

100

Patch now

HIGH 8.7EXPLOITEDREMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2019-11043 is a high-severity flaw (CVSS 8.7) affecting php, ubuntu linux, debian linux, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In PHP versions 7.1.x below 7.1.33, 7.2.x below 7.2.24 and 7.3.x below 7.3.11 in certain configurations of FPM setup it is possible to cause FPM module to write past allocated buffers into the space reserved for FCGI protocol data, thus opening the possibility of remote code execution.

Why this priority

High severity
EPSS top 1%: very likely to be exploited
Exploited in the wild (CISA KEV)
Used in ransomware campaigns
Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.7 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	99.8% (top 1%)
CISA exploited list	Yes, fix due 2022-04-15, used in ransomware
Weakness	CWE-120, CWE-787
Published	2019-10-28
Last modified	2026-06-17

Publisher (CNA): PHP Group · Vendor: canonical · debian · fedoraproject · php · redhat · tenable

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

Am I affected?

Timeline

2019-10-28 15:15 UTCPublished CVE record published
2022-03-25Exploited Added to the CISA Known Exploited Vulnerabilities list
2022-04-15Deadline CISA due date for US federal agencies to patch
2026-06-17 02:12 UTCUpdated Record last modified

php php UPGRADE

Affected: >= 7.1.0 and < 7.1.33 · >= 7.2.0 and < 7.2.24 · >= 7.3.0 and < 7.3.11

Fixed in: 7.1.33, 7.2.24, 7.3.11

Safe to downgrade to: a release before 7.1.0

1. Check installed version

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

2. UPGRADE to 7.1.33 (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 7.1.0 (Debian / Ubuntu)

apt-cache madison php sudo apt install php=<VERSION_BEFORE_7.1.0> 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_7.1.0> 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.

canonical ubuntu linux MITIGATE

Affected: 12.04 · 14.04 · 16.04 · 18.04 · 19.04 · 19.10

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: 9.0 · 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0

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.

fedoraproject fedora MITIGATE

Affected: 29 · 30 · 31

Fixed in: no fixed release known

Safe to downgrade to: a release before 29

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.

tenable tenable.sc UPGRADE

Affected: < 5.19.0

Fixed in: 5.19.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy tenable.sc || rpm -q tenable.sc || tenable.sc --version

2. UPGRADE to 5.19.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade tenable.sc

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tenable.sc

Note

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

redhat software collections DOWNGRADE

Affected: 1.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0

1. Check installed version

apt-cache policy software-collections || rpm -q software-collections || software-collections --version

2. No fixed release: DOWNGRADE to a release before 1.0 (Debian / Ubuntu)

apt-cache madison software-collections sudo apt install software-collections=<VERSION_BEFORE_1.0> sudo apt-mark hold software-collections

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

dnf --showduplicates list software-collections sudo dnf downgrade software-collections-<VERSION_BEFORE_1.0> sudo dnf versionlock add software-collections

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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora ELN · python-discovery · FIXED · 1.9.0-1.eln159 · FEDORA-2026-7a881c0c99 · source

sudo dnf upgrade --advisory=FEDORA-2026-7a881c0c99

Fedora 46 · pipx · FIXED · 1.18.11-1.fc46 · FEDORA-2026-443a765287 · source

sudo dnf upgrade --advisory=FEDORA-2026-443a765287

RHEL 6 · php · FIXED · php-5.3.3-50.el6_10

sudo dnf upgrade --advisory=RHSA-2019:3287 rpm -q php

RHEL 7 · php · FIXED · php-5.4.16-46.1.el7_7

sudo dnf upgrade --advisory=RHSA-2019:3286 rpm -q php

RHEL 7.6 Extended Update Support · php · FIXED · php-5.4.16-46.1.el7_6

sudo dnf upgrade --advisory=RHSA-2020:2835 rpm -q php

RHEL 5 · php · NOT AFFECTED

RHEL 5 · php53 · NOT AFFECTED

Amazon Linux 2 · see advisory · FIXED · ALAS2-2019-1344 · source

sudo yum update --advisory=ALAS2-2019-1344

Amazon Linux 1 · see advisory · FIXED · ALAS-2019-1315 · source

sudo yum update --advisory=ALAS-2019-1315

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: neex/phuip-fpizdam (1837 stars)
GitHub PoC: theMiddleBlue/CVE-2019-11043 (148 stars)
GitHub PoC: jas502n/CVE-2019-11043 (105 stars)
Write-up: hackerone.com/reports/722327
Exploit-DB: PHP-FPM - Underflow Remote Code Execution (Metasploit)
Exploit-DB: PHP-FPM + Nginx - Remote Code Execution
Metasploit: PHP-FPM Underflow RCE
Nuclei scan template: PHP-FPM Path Info Buffer Underflow - Remote Code Execution

Advisories and coverage

Research and news

Vulners Bulletins: Exploit for Classic Buffer Overflow in Php 2026-10-31
Tenable Research: php2shell (CVE-2026-109618, CVE-2026-109619): Frequently asked questions about critical PHP remote code execution vulnerabilities 2026-10-21

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-2019-11043?

php: upgrade to 7.1.33, 7.2.24, 7.3.11; ubuntu linux: mitigate or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2019-11043 being exploited?

Yes. CVE-2019-11043 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2019-11043 affect?

CVE-2019-11043 affects php, ubuntu linux, debian linux. Severity is high (CVSS 8.7). In PHP versions 7.1.x below 7.1.33, 7.2.x below 7.2.24 and 7.3.x below 7.3.11 in certain configurations of FPM setup it is possible to cause FPM module to write past allocated buffers into the space reserved for FCGI protocol data, thus ope

How urgent is CVE-2019-11043?

Priority 100/100. High severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Used in ransomware campaigns; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

PHP vulnerabilities · Ubuntu vulnerabilities · Debian vulnerabilities

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References

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