CVE-2021-21806

Name: CVE-2021-21806
Creator: NVD / NIST
Published: 2021-07-08T12:15:10.013+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 2.82%

Last modified Jun 17, 2026

CVE-2021-21806 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. An exploitable use-after-free vulnerability exists in WebKitGTK browser version 2.30.3 x64. A specially crafted HTML web page can cause a use-after-free condition, resulting in remote code execution. EPSS estimates a 2.82% chance of exploitation in the next 30 days.

Description

An exploitable use-after-free vulnerability exists in WebKitGTK browser version 2.30.3 x64. A specially crafted HTML web page can cause a use-after-free condition, resulting in remote code execution. The victim needs to visit a malicious web site to trigger the vulnerability.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

2.82%

84.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

Affected Software

Vendor	Product	Versions
Webkitgtk	Webkitgtk	2.30.3

References

http://www.openwall.com/lists/oss-security/2021/07/23/1Mailing List, Third Party Advisory
https://talosintelligence.com/vulnerability_reports/TALOS-2020-1214Exploit, Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/07/23/1Mailing List, Third Party Advisory
https://talosintelligence.com/vulnerability_reports/TALOS-2020-1214Exploit, Third Party Advisory

Timeline

Published: Jul 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21806?

How severe is CVE-2021-21806?

CVE-2021-21806 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 2.82% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21806?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21806?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST