CVE-2021-26272: It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste c

This month

MEDIUM 6.5UPGRADEDOWNGRADEUPGRADE

CVE-2021-26272 is a medium-severity flaw (CVSS 6.5) affecting ckeditor, agile product lifecycle management, application express. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted URL-like text into the editor, and then press Enter or Space (in the Autolink plugin).

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Weakness	CWE-829
Published	2021-01-26
Last modified	2026-08-25

Publisher (CNA): MITRE · Vendor: ckeditor · oracle

Last updated 2026-08-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-01-26 21:15 UTCPublished CVE record published
2026-08-25 16:28 UTCUpdated Record last modified

ckeditor ckeditor UPGRADE

Affected: >= 4.0 and < 4.16

Fixed in: 4.16

Safe to downgrade to: a release before 4.0

1. Check installed version

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

2. UPGRADE to 4.16 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade ckeditor

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 4.0 (Debian / Ubuntu)

apt-cache madison ckeditor sudo apt install ckeditor=<VERSION_BEFORE_4.0> sudo apt-mark hold ckeditor

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

dnf --showduplicates list ckeditor sudo dnf downgrade ckeditor-<VERSION_BEFORE_4.0> sudo dnf versionlock add ckeditor

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.

oracle agile product lifecycle management DOWNGRADE

Affected: 9.3.5 · 9.3.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.3.5

1. Check installed version

apt-cache policy agile-product-lifecycle-management || rpm -q agile-product-lifecycle-management || agile-product-lifecycle-management --version

2. No fixed release: DOWNGRADE to a release before 9.3.5 (Debian / Ubuntu)

apt-cache madison agile-product-lifecycle-management sudo apt install agile-product-lifecycle-management=<VERSION_BEFORE_9.3.5> sudo apt-mark hold agile-product-lifecycle-management

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

dnf --showduplicates list agile-product-lifecycle-management sudo dnf downgrade agile-product-lifecycle-management-<VERSION_BEFORE_9.3.5> sudo dnf versionlock add agile-product-lifecycle-management

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.

oracle application express UPGRADE

Affected: < 21.1.0

Fixed in: 21.1.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy application-express || rpm -q application-express || application-express --version

2. UPGRADE to 21.1.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade application-express

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade application-express

Note

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

oracle banking party management DOWNGRADE

Affected: 2.7.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.7.0

1. Check installed version

apt-cache policy banking-party-management || rpm -q banking-party-management || banking-party-management --version

2. No fixed release: DOWNGRADE to a release before 2.7.0 (Debian / Ubuntu)

apt-cache madison banking-party-management sudo apt install banking-party-management=<VERSION_BEFORE_2.7.0> sudo apt-mark hold banking-party-management

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

dnf --showduplicates list banking-party-management sudo dnf downgrade banking-party-management-<VERSION_BEFORE_2.7.0> sudo dnf versionlock add banking-party-management

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.

oracle commerce merchandising UPGRADE

Affected: >= 11.3.0 and <= 11.3.2 · 11.1.0 · 11.2.0

Fixed in: newer than 11.3.2

Safe to downgrade to: a release before 11.1.0

1. Check installed version

apt-cache policy commerce-merchandising || rpm -q commerce-merchandising || commerce-merchandising --version

2. UPGRADE to newer than 11.3.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade commerce-merchandising

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade commerce-merchandising

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 11.1.0 (Debian / Ubuntu)

apt-cache madison commerce-merchandising sudo apt install commerce-merchandising=<VERSION_BEFORE_11.1.0> sudo apt-mark hold commerce-merchandising

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

dnf --showduplicates list commerce-merchandising sudo dnf downgrade commerce-merchandising-<VERSION_BEFORE_11.1.0> sudo dnf versionlock add commerce-merchandising

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.

oracle financial services analytical applications infrastructure UPGRADE

Affected: >= 8.0.6 and <= 8.0.9 · 8.1.0 · 8.1.1

Fixed in: newer than 8.0.9

Safe to downgrade to: a release before 8.0.6

1. Check installed version

apt-cache policy financial-services-analytical-applications-infrastructure || rpm -q financial-services-analytical-applications-infrastructure || financial-services-analytical-applications-infrastructure --version

2. UPGRADE to newer than 8.0.9 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade financial-services-analytical-applications-infrastructure

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade financial-services-analytical-applications-infrastructure

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 8.0.6 (Debian / Ubuntu)

apt-cache madison financial-services-analytical-applications-infrastructure sudo apt install financial-services-analytical-applications-infrastructure=<VERSION_BEFORE_8.0.6> sudo apt-mark hold financial-services-analytical-applications-infrastructure

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

dnf --showduplicates list financial-services-analytical-applications-infrastructure sudo dnf downgrade financial-services-analytical-applications-infrastructure-<VERSION_BEFORE_8.0.6> sudo dnf versionlock add financial-services-analytical-applications-infrastructure

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.

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-2021-26272?

ckeditor: upgrade to 4.16; agile product lifecycle management: downgrade or apply the listed mitigation; application express: upgrade to 21.1.0. Exact commands for each OS are on this page.

Is CVE-2021-26272 being exploited?

CVE-2021-26272 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-2021-26272 affect?

CVE-2021-26272 affects ckeditor, agile product lifecycle management, application express. Severity is medium (CVSS 6.5). It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted URL-like text into the editor, and then press Enter or Space (in the Autolink plugin).

How urgent is CVE-2021-26272?

Priority 44/100. No elevated risk signals yet.

Related CVEs

CVE-2021-41164 HIGH 8.2 UPGRADE UPGRADE CKEditor4 is an open source WYSIWYG HTML editor
CVE-2021-26271 MEDIUM 6.5 UPGRADE DOWNGRADE It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste c
CVE-2020-27193 MEDIUM 6.1 DOWNGRADE DOWNGRADE A cross-site scripting (XSS) vulnerability in the Color Dialog plugin for CKEditor 4.15.0 allows remote attack
CVE-2023-31541 CRITICAL 9.8 DOWNGRADE A unrestricted file upload vulnerability was discovered in the ‘Browse and upload images’ feature of the CKEdi
CVE-2024-43407 MEDIUM 6.1 UPGRADE CKEditor4 is an open source what-you-see-is-what-you-get HTML editor

References

← Back to latest CVEs