CVE-2022-26635: PHP-Memcached v2.2.0 and below contains an improper NULL termination which allows attackers to execute CLRF in

Q: How do I fix CVE-2022-26635?

memcached: upgrade to newer than 2.2.0. Exact commands for each OS are on this page.

Q: Is CVE-2022-26635 being exploited?

CVE-2022-26635 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2022-26635 affect?

CVE-2022-26635 affects memcached. Severity is critical (CVSS 9.8). PHP-Memcached v2.2.0 and below contains an improper NULL termination which allows attackers to execute CLRF injection. Note: Third parties have disputed this as not affecting PHP-Memcached directly.

Q: How urgent is CVE-2022-26635?

Priority 69/100. Critical severity; EPSS top 2%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2022-26635 is a critical-severity flaw (CVSS 9.8) affecting memcached. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

PHP-Memcached v2.2.0 and below contains an improper NULL termination which allows attackers to execute CLRF injection. Note: Third parties have disputed this as not affecting PHP-Memcached directly.

Why this priority

Critical severity
EPSS top 2%: very likely to be exploited
Public exploit reference
Remotely exploitable, no login, no user action

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	21.4% (top 2%)
CISA exploited list	No
Published	2022-04-05
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: php

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

Am I affected?

Timeline

2022-04-05 17:15 UTCPublished CVE record published
2026-06-17 04:35 UTCUpdated Record last modified

php memcached UPGRADE

Affected: <= 2.2.0

Fixed in: newer than 2.2.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 2.2.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade memcached

Note

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

Exact fixes by distribution

Fedora 46 · nemo · FIXED · 6.8.0-1.fc46 · FEDORA-2026-0edead723f · source

sudo dnf upgrade --advisory=FEDORA-2026-0edead723f

Fedora ELN · composer · FIXED · 2.11.1-1.eln159 · FEDORA-2026-cb4f992456 · source

sudo dnf upgrade --advisory=FEDORA-2026-cb4f992456

Ubuntu 20.04 · php-memcached · NOT AFFECTED

Ubuntu 22.04 · php-memcached · NOT AFFECTED

Alpine 3.20 · memcached · NOT AFFECTED

Alpine 3.21 · memcached · NOT AFFECTED

Alpine 3.22 · memcached · NOT AFFECTED

Alpine 3.23 · memcached · NOT AFFECTED

Amazon Linux 1 · see advisory · FIXED · ALAS-2023-1674 · source

sudo yum update --advisory=ALAS-2023-1674

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: xhzeem.me/posts/Php5-memcached-Injection-Bypass/read/

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-2022-26635?

memcached: upgrade to newer than 2.2.0. Exact commands for each OS are on this page.

Is CVE-2022-26635 being exploited?

CVE-2022-26635 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-2022-26635 affect?

CVE-2022-26635 affects memcached. Severity is critical (CVSS 9.8). PHP-Memcached v2.2.0 and below contains an improper NULL termination which allows attackers to execute CLRF injection. Note: Third parties have disputed this as not affecting PHP-Memcached directly.

How urgent is CVE-2022-26635?

Priority 69/100. Critical severity; EPSS top 2%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities · Memcached vulnerabilities

Related CVEs

CVE-2023-46853 CRITICAL 9.8 UPGRADE In Memcached before 1.6.22, an off-by-one error exists when processing proxy requests in proxy mode, if \n is
CVE-2023-46852 HIGH 7.5 UPGRADE In Memcached before 1.6.22, a buffer overflow exists when processing multiget requests in proxy mode, if there
CVE-2022-48571 HIGH 7.5 DOWNGRADE memcached 1.6.7 allows a Denial of Service via multi-packet uploads in UDP.
CVE-2021-37519 MEDIUM 5.5 DOWNGRADE Buffer Overflow vulnerability in authfile.c memcached 1.6.9 allows attackers to cause a denial of service via
CVE-2020-22570 HIGH 7.5 UPGRADE Memcached 1.6.0 before 1.6.3 allows remote attackers to cause a denial of service (daemon crash) via a crafted

References

← Back to latest CVEs