CVE-2020-27824 Memory corruption in openjpeg

What is CVE-2020-27824?

CVE-2020-27824 is a medium-severity memory corruption vulnerability in Debian Debian Linux, published on 13 May 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

A flaw was found in OpenJPEG’s encoder in the opj_dwt_calc_explicit_stepsizes() function. This flaw allows an attacker who can supply crafted input to decomposition levels to cause a buffer overflow. The highest threat from this vulnerability is to system availability.

Weakness: CWE-125, CWE-20

Which versions are affected by CVE-2020-27824?

It affects 4 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Redhat Enterprise Linux, Uclouvain Openjpeg.

How do I fix CVE-2020-27824?

Apply the vendor's patch.

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

Is CVE-2020-27824 being exploited?

There is no known exploitation of CVE-2020-27824 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

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 ALPINE-CVE-2020-27824, AZL-45282, DEBIAN-CVE-2020-27824, GHSA-4w56-x77j-f3vc, JLSEC-2026-537, UBUNTU-CVE-2020-27824.