CVE-2021-4063 Use after free in Chrome

What is CVE-2021-4063?

CVE-2021-4063 is a high-severity use after free vulnerability in Debian Debian Linux, published on 23 Dec 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Use after free in developer tools in Google Chrome prior to 96.0.4664.93 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

Weakness: CWE-416

Which versions are affected by CVE-2021-4063?

It affects 3 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Google Chrome.

How do I fix CVE-2021-4063?

Upgrade to a fixed version.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2021-4063 being exploited?

There is no known exploitation of CVE-2021-4063 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-4063, GHSA-3v67-76rr-2qc3, UBUNTU-CVE-2021-4063.