CVE-2026-12087: Socket versions before 2.041 for Perl have an out-of-bounds heap read. In Socket.xs, pack_ip_mreq_source() ch

This month

CRITICAL 9.1REMOTE

CVE-2026-12087 is a critical-severity flaw (CVSS 9.1) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Socket versions before 2.041 for Perl have an out-of-bounds heap read. In Socket.xs, pack_ip_mreq_source() checks the length of its source argument before the argument is read, so the check tests the byte length carried over from the preceding multiaddr argument instead. Both addresses occupy a 4-byte field, so a valid multiaddr lets a source of any length pass the check, and the source is then copied into the 4-byte imr_sourceaddr field with a

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	No
Weakness	CWE-125, CWE-805
Published	2026-06-15
Last modified	2026-10-25

Publisher (CNA): CPANSec

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-06-15 22:16 UTCPublished CVE record published
2026-10-25 23:10 UTCUpdated Record last modified

Exact fixes by distribution

Fedora 46 · log4cplus · FIXED · 2.2.0.1-2.fc46 · FEDORA-2026-fc241370c9 · source

sudo dnf upgrade --advisory=FEDORA-2026-fc241370c9

Fedora ELN · velocitty · FIXED · 1.0.3-2.eln159 · FEDORA-2026-edae8cd295 · source

sudo dnf upgrade --advisory=FEDORA-2026-edae8cd295

Ubuntu 24.04 · perl · FIXED · 5.38.2-3.2ubuntu0.4

sudo apt update && sudo apt install --only-upgrade perl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' perl)" ge "5.38.2-3.2ubuntu0.4" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 20.04 · perl · FIXED · 5.30.0-9ubuntu0.5+esm3

sudo apt update && sudo apt install --only-upgrade perl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' perl)" ge "5.30.0-9ubuntu0.5+esm3" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · perl · FIXED · 5.34.0-3ubuntu1.8

sudo apt update && sudo apt install --only-upgrade perl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' perl)" ge "5.34.0-3ubuntu1.8" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · libsocket-perl · NO FIX YET

Debian 13 · libsocket-perl · FIXED · 2.038-1+deb13u1

sudo apt update && sudo apt install --only-upgrade libsocket-perl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' libsocket-perl)" ge "2.038-1+deb13u1" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · perl · FIXED · 5.36.0-7+deb12u4

sudo apt update && sudo apt install --only-upgrade perl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' perl)" ge "5.36.0-7+deb12u4" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · perl · FIXED · 5.40.1-6+deb13u1

sudo apt update && sudo apt install --only-upgrade perl dpkg --compare-versions "$(dpkg-query -W -f='${Version}' perl)" ge "5.40.1-6+deb13u1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 10 · perl-Socket · DEFERRED

RHEL 10 · perl-Socket6 · DEFERRED

RHEL 6 · perl-Socket6 · DEFERRED

RHEL 7 · perl-Socket · DEFERRED

RHEL 7 · perl-Socket6 · DEFERRED

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2026-2161 · source

sudo dnf update --advisory=ALAS2023-2026-2161

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: gduma-phData/patch-CVE-2026-12087 (0 stars)

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-2026-12087?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-12087 being exploited?

CVE-2026-12087 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-2026-12087 affect?

CVE-2026-12087 affects affected software. Severity is critical (CVSS 9.1). Socket versions before 2.041 for Perl have an out-of-bounds heap read. In Socket.xs, pack_ip_mreq_source() checks the length of its source argument before the argument is read, so the check tests the byte length carried over from the prece

How urgent is CVE-2026-12087?

Priority 49/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

Perl vulnerabilities

References

← Back to latest CVEs