CVE-2024-56406 Perl is vulnerable to a heap buffer overflow when transliterating non-ASCII bytes

What is CVE-2024-56406?

CVE-2024-56406 is a high-severity memory corruption vulnerability in perl, published on 13 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A heap buffer overflow vulnerability was discovered in Perl.

Release branches 5.34, 5.36, 5.38 and 5.40 are affected, including development versions from 5.33.1 through 5.41.10.

When there are non-ASCII bytes in the left-hand-side of the `tr` operator, `S_do_trans_invmap` can overflow the destination pointer `d`.

   $ perl -e '$_ = "\x{FF}" x 1000000; tr/\xFF/\x{100}/;'    Segmentation fault (core dumped)

It is believed that this vulnerability can enable Denial of Service and possibly Code Execution attacks on platforms that lack sufficient defenses.

Weakness: CWE-787, CWE-122

Which versions are affected by CVE-2024-56406?

It affects 1 product.

Products include Perl Perl.

How do I fix CVE-2024-56406?

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-2024-56406 being exploited?

There is no known exploitation of CVE-2024-56406 in the wild and no public exploit code.

Other vulnerabilities in perl

• CVE-2026-4176 Supply chain in perl Critical 9.8
• CVE-2022-48522 Memory corruption in n/a Critical 9.8
• CVE-2017-12814 Memory corruption in n/a Critical 9.8
• CVE-2015-8608 Memory corruption in n/a Critical 9.8
• CVE-2026-13221 Integer overflow in perl:perl Critical 9.1

Sources

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

Also known as ALPINE-CVE-2024-56406, ALSA-2025:7500, AZL-60384, AZL-60409, BELL-CVE-2024-56406, DEBIAN-CVE-2024-56406 and 16 more.