CVE-2021-39253 Memory corruption in n/a

What is CVE-2021-39253?

CVE-2021-39253 is a medium-severity memory corruption vulnerability in Debian Debian Linux, published on 7 Sep 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A crafted NTFS image can cause an out-of-bounds read in ntfs_runlists_merge_i in NTFS-3G < 2021.8.22.

Weakness: CWE-20, CWE-125

Which versions are affected by CVE-2021-39253?

It affects 3 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Tuxera Ntfs-3g.

How do I fix CVE-2021-39253?

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-2021-39253 being exploited?

There is no known exploitation of CVE-2021-39253 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 AZL-6758, DEBIAN-CVE-2021-39253, GHSA-5g77-57xq-24cv, UBUNTU-CVE-2021-39253.