Medium

Clipboard feature vulnerability allowing to inject arbitrary HTML into the editor using paste functionality

  • Disclosed: 23.08.2021
  • Updated: 11.10.2026 10:22

Affected packages

The vulnerability has been discovered in clipboard plugin. All plugins with clipboard plugin dependency are affected:

Impact

A potential vulnerability has been discovered in CKEditor 4 Clipboard package. The vulnerability allowed to abuse paste functionality using malformed HTML, which could result in injecting arbitrary HTML into the editor. It affects all users using the CKEditor 4 plugins listed above at version >= 4.5.2.

Patches

The problem has been recognized and patched. The fix will be available in version 4.16.2.

For more information

Email us at security@cksource.com if you have any questions or comments about this advisory.

Acknowledgements

The CKEditor 4 team would like to thank Anton Subbotin (skavans) for recognizing and reporting this vulnerability.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
npm package ckeditor4 >= 4.5.2, < 4.16.2 4.16.2

References

CVSS score 4.6/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
Weakness (CWE)
CWE-79, CWE-94
Platform
npm
Package
ckeditor4
Disclosed
23.08.2021
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-7889-rm5j-hpgg - CC BY 4.0

Vulnerability history: ckeditor4

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (15) in the archive
Total entries
15
First → latest
05.2021 08.2024
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • High 4
  • Medium 11

Disclosures per year

  1. 2021: 8
  2. 2022: 2
  3. 2023: 0
  4. 2024: 5
  5. 2025: 0
  6. 2026: 0
Severity:
  1. High · 8.2 CVE-2021-41165 < 4.17.0 4.17.0
  2. Clipboard feature vulnerability allowing to inject arbitrary HTML into the editor using paste functionality this entry
    Medium · 4.6 CVE-2021-32809 >= 4.5.2, < 4.16.2 4.16.2

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