CVE-2021-26271

Publication date 26 January 2021

Last updated 26 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted text into the Styles input of specific dialogs (in the Advanced Tab for Dialogs plugin).

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
ckeditor	26.04 LTS resolute	Not in release
	25.10 questing	Not affected
	25.04 plucky	Not affected
	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Not affected
	22.04 LTS jammy	Not affected
	21.10 impish	Fixed 4.16.0+dfsg-2
	21.04 hirsute	Ignored end of life
	20.10 groovy	Ignored end of life
	20.04 LTS focal	Ignored end of standard support, was needs-triage
	18.04 LTS bionic	Ignored end of standard support, was needs-triage
	16.04 LTS xenial	Ignored end of standard support, was needed
	14.04 LTS trusty	Not in release

Notes

litios

No specific patch was found

Severity score breakdown

Parameter	Value
Base score	6.5 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	Required
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H