CVE-2020-6556 Memory corruption in Chrome

What is CVE-2020-6556?

CVE-2020-6556 is a high-severity memory corruption vulnerability in Debian Debian Linux, published on 21 Sep 2020. 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

Heap buffer overflow in SwiftShader in Google Chrome prior to 84.0.4147.135 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

Weakness: CWE-787

Which versions are affected by CVE-2020-6556?

It affects 4 products.

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

How do I fix CVE-2020-6556?

Upgrade to a fixed version.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2020-6556 being exploited?

There is no known exploitation of CVE-2020-6556 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-2020-6556, GHSA-fffr-w5cq-wghr, UBUNTU-CVE-2020-6556, openSUSE-SU-2020:1260-1, openSUSE-SU-2020:1263-1.