CVE-2026-57432: Perl versions before 5.40.5-RC1, from 5.41.0 before 5.42.3-RC1, from 5.43.0 before 5.43.11 have an integer ove

Q: How do I fix CVE-2026-57432?

perl: upgrade to newer than 5.43.10. Exact commands for each OS are on this page.

Q: Is CVE-2026-57432 being exploited?

CVE-2026-57432 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-57432 affect?

CVE-2026-57432 affects perl. Severity is high (CVSS 8.4). Perl versions before 5.40.5-RC1, from 5.41.0 before 5.42.3-RC1, from 5.43.0 before 5.43.11 have an integer overflow in S_measure_struct leading to an out-of-bounds heap read in pack and unpack. S_measure_struct adds each item's size times

Routine

HIGH 8.4UPGRADE

CVE-2026-57432 is a high-severity flaw (CVSS 8.4) affecting perl. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Perl versions before 5.40.5-RC1, from 5.41.0 before 5.42.3-RC1, from 5.43.0 before 5.43.11 have an integer overflow in S_measure_struct leading to an out-of-bounds heap read in pack and unpack. S_measure_struct adds each item's size times its repeat count to a running total with no overflow check, so a large repeat count in a pack or unpack template wraps the signed SSize_t total negative. The @, X, and x position codes then guard their moves wi

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.4 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.2% (top 89%)
CISA exploited list	No
Weakness	CWE-125, CWE-190
Published	2026-07-13
Last modified	2026-10-24

Publisher (CNA): CPANSec · Vendor: perl

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-13 17:17 UTCPublished CVE record published
2026-10-24 22:10 UTCUpdated Record last modified

perl perl UPGRADE

Affected: <= 5.43.10

Fixed in: newer than 5.43.10

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy perl || rpm -q perl || perl --version

2. UPGRADE to newer than 5.43.10 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade perl

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade perl

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Advisories and coverage

Official advisories

Amazon Linux 2023 ALAS: ALAS2023-2026-3211 (medium): perl 2026-10-12
Amazon Linux 2 ALAS: ALAS2-2026-3997 (medium): perl 2026-10-12

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-57432?

perl: upgrade to newer than 5.43.10. Exact commands for each OS are on this page.

Is CVE-2026-57432 being exploited?

CVE-2026-57432 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-57432 affect?

CVE-2026-57432 affects perl. Severity is high (CVSS 8.4). Perl versions before 5.40.5-RC1, from 5.41.0 before 5.42.3-RC1, from 5.43.0 before 5.43.11 have an integer overflow in S_measure_struct leading to an out-of-bounds heap read in pack and unpack. S_measure_struct adds each item's size times

How urgent is CVE-2026-57432?

Priority 32/100. High severity

Software pages

Perl vulnerabilities

Related CVEs

CVE-2026-13221 CRITICAL 9.1 UPGRADE Perl versions before 5.40.5-RC1, from 5.41.0 before 5.42.3-RC1, from 5.43.0 before 5.43.10 produce silently in

References

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