CVE-2018-7584: In PHP through 5.6.33, 7.0.x before 7.0.28, 7.1.x through 7.1.14, and 7.2.x through 7.2.2, there is a stack-ba

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CRITICAL 9.8REMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2018-7584 is a critical-severity flaw (CVSS 9.8) affecting php, ubuntu linux, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In PHP through 5.6.33, 7.0.x before 7.0.28, 7.1.x through 7.1.14, and 7.2.x through 7.2.2, there is a stack-based buffer under-read while parsing an HTTP response in the php_stream_url_wrap_http_ex function in ext/standard/http_fopen_wrapper.c. This subsequently results in copying a large string.

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	87.3% (top 1%)
CISA exploited list	No
Weakness	CWE-119
Published	2018-03-01
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: canonical · debian · php

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

Am I affected?

Timeline

2018-03-01 19:29 UTCPublished CVE record published
2026-06-17 02:03 UTCUpdated Record last modified

php php UPGRADE

Affected: <= 5.6.33 · >= 7.0.0 and < 7.0.28 · >= 7.1.0 and <= 7.1.14 · >= 7.2.0 and <= 7.2.2

Fixed in: 7.0.28

Safe to downgrade to: a release before 7.0.0

1. Check installed version

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

2. UPGRADE to 7.0.28 (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 7.0.0 (Debian / Ubuntu)

apt-cache madison php sudo apt install php=<VERSION_BEFORE_7.0.0> 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_7.0.0> 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 · 17.10

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: 7.0 · 8.0 · 9.0

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 ELN · makedumpfile · FIXED · 1.8.0-1.eln159 · FEDORA-2026-3bf4582b1f · source

sudo dnf upgrade --advisory=FEDORA-2026-3bf4582b1f

Fedora 46 · python-resend · FIXED · 2.50.1-1.fc46 · FEDORA-2026-8c29ba68cc · source

sudo dnf upgrade --advisory=FEDORA-2026-8c29ba68cc

RHEL 7 · php · FIXED · php-5.4.16-48.el7

sudo dnf upgrade --advisory=RHSA-2020:1112 rpm -q php

RHEL 5 · php · DEFERRED

RHEL 5 · php53 · DEFERRED

RHEL 6 · php · DEFERRED

RHEL 8 · php · NOT AFFECTED

Amazon Linux 1 · see advisory · FIXED · ALAS-2018-988 · source

sudo yum update --advisory=ALAS-2018-988

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: bugs.php.net/bug.php?id=75981
Write-up: hackerone.com/reports/320222
Write-up: www.exploit-db.com/exploits/44846/
Exploit-DB: PHP 7.2.2 - 'php_stream_url_wrap_http_ex' Buffer Overflow

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-2018-7584?

php: upgrade to 7.0.28; 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-2018-7584 being exploited?

CVE-2018-7584 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-2018-7584 affect?

CVE-2018-7584 affects php, ubuntu linux, debian linux. Severity is critical (CVSS 9.8). In PHP through 5.6.33, 7.0.x before 7.0.28, 7.1.x through 7.1.14, and 7.2.x through 7.2.2, there is a stack-based buffer under-read while parsing an HTTP response in the php_stream_url_wrap_http_ex function in ext/standard/http_fopen_wrappe

How urgent is CVE-2018-7584?

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

PHP vulnerabilities · Ubuntu vulnerabilities · Debian vulnerabilities

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References

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