CVE-2021-26271
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
02 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
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 1.99% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 80.5% of scored records. A rank, not a probability.
- NVD base score
- 6.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-08-25.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-01-26 20:39Z5 YR AGO
- Last updated
- 2024-08-03 20:19Z2 YR AGO
- Reserved
- 2021-01-26
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-829Inclusion of Functionality from Untrusted Control SphereBase
- Data version
- 5.1
- Document digest
- 563d766c578e27c5f03272eac2972a3c7958a2285e618e57ca4f66047d75e067
05 Affected products
06 References
- github.comhttps://github.com/ckeditor/ckeditor4/blob/major/CHANGES.md#ckeditor-416
- www.oracle.comhttps://www.oracle.com//security-alerts/cpujul2021.html
- ckeditor.comhttps://ckeditor.com/blog/CKEditor-4.16-with-improved-image-pasting-High-Contrast-support-and-a-new-color-API/#security-comes-first
- www.oracle.comhttps://www.oracle.com/security-alerts/cpuoct2021.html
07 Fixed in
Debian 12
- ckeditor Fixed in 4.16.0+dfsg-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- ckeditor No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 18.04 LTS
- ckeditor No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 20.04 LTS
- ckeditor No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.