CVE-2024-43407: CKEditor4 is an open source what-you-see-is-what-you-get HTML editor

Routine

MEDIUM 6.1UPGRADE

CVE-2024-43407 is a medium-severity flaw (CVSS 6.1) affecting ckeditor. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

CKEditor4 is an open source what-you-see-is-what-you-get HTML editor. A potential vulnerability has been discovered in CKEditor 4 Code Snippet GeSHi plugin. The vulnerability allowed a reflected XSS attack by exploiting a flaw in the GeSHi syntax highlighter library hosted by the victim. The GeSHi library was included as a vendor dependency in CKEditor 4 source files. In a specific scenario, an attacker could craft a malicious script that could b

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 61%)
CISA exploited list	No
Weakness	CWE-79
Published	2024-08-21
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: ckeditor

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

Am I affected?

Timeline

2024-08-21 15:15 UTCPublished CVE record published
2026-06-17 07:50 UTCUpdated Record last modified

ckeditor ckeditor UPGRADE

Affected: >= 4.0 and < 4.25.0

Fixed in: 4.25.0

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 4.25.0 (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.

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-2024-43407?

ckeditor: upgrade to 4.25.0. Exact commands for each OS are on this page.

Is CVE-2024-43407 being exploited?

CVE-2024-43407 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-2024-43407 affect?

CVE-2024-43407 affects ckeditor. Severity is medium (CVSS 6.1). CKEditor4 is an open source what-you-see-is-what-you-get HTML editor. A potential vulnerability has been discovered in CKEditor 4 Code Snippet GeSHi plugin. The vulnerability allowed a reflected XSS attack by exploiting a flaw in the GeSHi

How urgent is CVE-2024-43407?

Priority 31/100. No elevated risk signals yet.

Related CVEs

CVE-2021-41164 HIGH 8.2 UPGRADE UPGRADE CKEditor4 is an open source WYSIWYG HTML editor
CVE-2021-26272 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-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

References

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