How severe is CVE-2026-28343?

CVE-2026-28343 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-28343 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-28343?

CVE-2026-28343 affects Ckeditor Ckeditor5. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-28343?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-28343 have an EU (EUVD) identifier?

Yes. CVE-2026-28343 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9867.

When was CVE-2026-28343 published?

CVE-2026-28343 was published on 2026-03-05 and last updated on 2026-06-17.

CVE-2026-28343

CVE-2026-28343 is a medium-severity vulnerability in Ckeditor Ckeditor5 with a CVSS 3.x base score of 6.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.4)
EPSS exploit prediction: 0% (18th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-9867
Weakness: CWE-79
Affected product: Ckeditor Ckeditor5
Published: 2026-03-05
Last modified: 2026-06-17

Description

CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. Starting in version 29.0.0 and prior to version 47.6.0, a cross-site scripting (XSS) vulnerability has been discovered in the General HTML Support feature. This vulnerability could be triggered by inserting specially crafted markup, leading to unauthorized JavaScript code execution, if the editor instance used an unsafe General HTML Support configuration. This issue has been patched in version 47.6.0.

Frequently asked questions

What is CVE-2026-28343?: CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. Starting in version 29.0.0 and prior to version 47.6.0, a cross-site scripting (XSS) vulnerability has been discovered in the General HTML Support feature. This vulnerability could be triggered by inserting specially crafted markup, leading to unauthorized JavaScript code execution, if the editor instance used an unsafe General HTML Support configuration. This issue has been patched in version 47.6.0.
How severe is CVE-2026-28343?: CVE-2026-28343 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-28343 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-28343?: CVE-2026-28343 affects Ckeditor Ckeditor5. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-28343?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-28343 have an EU (EUVD) identifier?: Yes. CVE-2026-28343 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9867.
When was CVE-2026-28343 published?: CVE-2026-28343 was published on 2026-03-05 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:ckeditor:ckeditor5:*:*:*:*:*:*:*:*

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