CVE-2021-32809 [Medium] | XSS in Ckeditor

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.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-04-13	0.32%	0.24%	-0.09%
2	2026-03-04	0.13%	0.32%	+0.19%
3	2026-03-01	—	0.13%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-04-13

0.32%

0.24%

-0.09%

2026-03-04

0.13%

0.32%

+0.19%

2026-03-01

—

0.13%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
4.6	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:L) Some sensitive info could get out, but not a total data dump. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:N) Service keeps running; no real outage angle.	2.1	2.5	[email protected]
5.4	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:L) Some sensitive info could get out, but not a total data dump. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:N) Service keeps running; no real outage angle.	2.3	2.7	[email protected]
3.5	2.0	LOW	`AV:N/AC:M/Au:S/C:N/I:P/A:N` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:S) A single authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:N) No availability impact.	6.8	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

4.6

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L): Some sensitive info could get out, but not a total data dump.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N): Service keeps running; no real outage angle.

2.1

2.5

[email protected]

5.4

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L): Some sensitive info could get out, but not a total data dump.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N): Service keeps running; no real outage angle.

2.3

2.7

[email protected]

3.5

2.0

LOW

AV:N/AC:M/Au:S/C:N/I:P/A:N Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S): A single authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:N): No availability impact.

6.8

2.9

[email protected]

OS Trackers for CVE-2021-32809

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2021-32809 not yet assigned priority: Debian including 1 source packages (ckeditor), 2 status rows across 2 suites (bookworm, bullseye): open 1, resolved 1.	https://security-tracker.debian.org/tracker/CVE-2021-32809
`ubuntu`	medium	CVE-2021-32809 medium priority: Ubuntu including 1 source packages (ckeditor), 8 status rows across 8 suites (bionic, focal, hirsute, impish, jammy, trusty, upstream, xenial): released 4, not-affected 2, DNE 1, ignored 1.	https://ubuntu.com/security/CVE-2021-32809

Affected software / configurations for CVE-2021-32809

Vendor	Product	Version	Raw CPE
ckeditor	ckeditor	>= 4.5.2, < 4.16.2	cpe:2.3:a:ckeditor:ckeditor::::::node.js::*
fedoraproject	fedora	33	cpe:2.3:o:fedoraproject:fedora:33:::::::*
fedoraproject	fedora	34	cpe:2.3:o:fedoraproject:fedora:34:::::::*
fedoraproject	fedora	35	cpe:2.3:o:fedoraproject:fedora:35:::::::*
oracle	application_express	< 21.1.4	cpe:2.3:a:oracle:application_express::::::::
oracle	banking_party_management	2.7.0	cpe:2.3:a:oracle:banking_party_management:2.7.0:::::::*
oracle	commerce_guided_search	11.3.2	cpe:2.3:a:oracle:commerce_guided_search:11.3.2:::::::*
oracle	commerce_merchandising	11.3.2	cpe:2.3:a:oracle:commerce_merchandising:11.3.2:::::::*
oracle	documaker	12.6.3	cpe:2.3:a:oracle:documaker:12.6.3:::::::*
oracle	documaker	12.6.4	cpe:2.3:a:oracle:documaker:12.6.4:::::::*
oracle	financial_services_analytical_applications_infrastructure	>= 8.0.7, <= 8.1.1	cpe:2.3:a:oracle:financial_services_analytical_applications_infrastructure::::::::
oracle	jd_edwards_enterpriseone_tools	< 9.2.6.0	cpe:2.3:a:oracle:jd_edwards_enterpriseone_tools::::::::
oracle	peoplesoft_enterprise_peopletools	8.57	cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.57:::::::*
oracle	peoplesoft_enterprise_peopletools	8.58	cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.58:::::::*
oracle	peoplesoft_enterprise_peopletools	8.59	cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.59:::::::*

References for CVE-2021-32809

URL	Tags
https://github.com/ckeditor/ckeditor4/security/advisories/GHSA-7889-rm5j-hpgg	Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NYA354LJP47KCVJMTUO77ZCX3ZK42G3T/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UVOYN2WKDPLKCNILIGEZM236ABQASLGW/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WAGNWHFIQAVCP537KFFS2A2GDG66J7XD/
https://www.oracle.com/security-alerts/cpujan2022.html	Patch Third Party Advisory
https://www.oracle.com/security-alerts/cpuoct2021.html	Patch Third Party Advisory

URL

CVE-2021-32809 | Arbitrary HTML injection vulnerability in ckeditor

Exploit prediction scoring system (EPSS) score for CVE-2021-32809

Common vulnerability scoring system (CVSS) metrics for CVE-2021-32809

Weakness enumeration for CVE-2021-32809

GitHub Security Advisory for CVE-2021-32809

OS Trackers for CVE-2021-32809

Affected software / configurations for CVE-2021-32809

References for CVE-2021-32809