CVE-2021-20312 Integer overflow in ImageMagick

What is CVE-2021-20312?

CVE-2021-20312 is a high-severity vulnerability in Debian Debian Linux, published on 11 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A flaw was found in ImageMagick in versions 7.0.11, where an integer overflow in WriteTHUMBNAILImage of coders/thumbnail.c may trigger undefined behavior via a crafted image file that is submitted by an attacker and processed by an application using ImageMagick. The highest threat from this vulnerability is to system availability.

Weakness: CWE-190

Which versions are affected by CVE-2021-20312?

It affects 2 products.

Products include Debian Debian Linux, Imagemagick Imagemagick.

How do I fix CVE-2021-20312?

Upgrade to a fixed version.

Is CVE-2021-20312 being exploited?

There is no known exploitation of CVE-2021-20312 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

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• 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-2021-20312, GHSA-7cgc-x5j3-p7hx, JLSEC-2026-887, UBUNTU-CVE-2021-20312.