CVE-2026-8376: 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 a heap buffer

Q: How do I fix CVE-2026-8376?

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

Q: Is CVE-2026-8376 being exploited?

CVE-2026-8376 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-2026-8376 affect?

CVE-2026-8376 affects perl. Severity is critical (CVSS 9.8). 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 a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds. Perl_study_chunk in regcomp_study.c ch

Q: How urgent is CVE-2026-8376?

Priority 50/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2026-8376 is a critical-severity flaw (CVSS 9.8) 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 a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds. Perl_study_chunk in regcomp_study.c checked the size of the joined substring buffer in characters rather than bytes. For a quantified fixed substring with a large minimum count, the byte length mincount * l could overflow SSize_t, producing an unde

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 58%)
CISA exploited list	No
Weakness	CWE-680
Published	2026-05-26
Last modified	2026-09-08

Publisher (CNA): CPANSec · Vendor: perl

Last updated 2026-09-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-26 00:16 UTCPublished CVE record published
2026-09-08 22:19 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.

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-2026-8376?

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

Is CVE-2026-8376 being exploited?

CVE-2026-8376 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-2026-8376 affect?

CVE-2026-8376 affects perl. Severity is critical (CVSS 9.8). 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 a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds. Perl_study_chunk in regcomp_study.c ch

How urgent is CVE-2026-8376?

Priority 50/100. Critical severity; Remotely exploitable, no login, no user action

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
CVE-2026-57432 HIGH 8.4 UPGRADE 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

References

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