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Fencer Vulns
medium 4.6

CVE-2021-32809 json

Arbitrary HTML injection vulnerability in ckeditor

published 2021-08-12 5 y ago modified 2026-07-08 4 mo ago also GHSA-7889-rm5j-hpgg , EUVD-2021-1613

cvss
4.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 68%
public exploits
0
none known

Summary

ckeditor is an open source WYSIWYG HTML editor with rich content support. A potential vulnerability has been discovered in CKEditor 4 [Clipboard](https://ckeditor.com/cke4/addon/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. The problem has been recognized and patched. The fix will be available in version 4.16.2.

Patch / fix

  • npm ckeditor4 4.16.2
  • ckeditor ckeditor 4.16.2
  • oracle application_express 21.1.4
  • oracle jd_edwards_enterpriseone_tools 9.2.6.0
  • ckeditor Debian 12 4.16.2+dfsg-1

debian advisories DEBIAN-CVE-2021-32809

  • ckeditor Ubuntu 18.04 LTS 4.5.7+dfsg-2ubuntu0.18.04.1
  • ckeditor Ubuntu 20.04 LTS 4.12.1+dfsg-1ubuntu0.1
  • ckeditor Ubuntu Pro 16.04 LTS 4.5.7+dfsg-2ubuntu0.16.04.1~esm1

ubuntu advisories UBUNTU-CVE-2021-32809

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-32809 updated cvss 4.6

ckeditor: clipboard feature vulnerability allowing to inject arbitrary HTML into the editor using paste functionality

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.19% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.6 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 3.5 AV:N/AC:M/Au:S/C:N/I:P/A:N
GitHub 3.1 4.6 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
npm ckeditor4
>=4.5.2, <4.16.2
4.16.2

Affected products

  • ckeditor ckeditor4

Classification

Weakness
  • CWE-94 Improper Control of Generation of Code
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.