CVE-2026-9334: Cpanel::JSON::XS versions before 4.41 for Perl allow type confusion via duplicate object keys when dupkeys_as_

Q: How do I fix CVE-2026-9334?

cpanel\: upgrade to 4.41. Exact commands for each OS are on this page.

Q: Is CVE-2026-9334 being exploited?

CVE-2026-9334 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-2026-9334 affect?

CVE-2026-9334 affects cpanel\. Severity is high (CVSS 7.3). Cpanel::JSON::XS versions before 4.41 for Perl allow type confusion via duplicate object keys when dupkeys_as_arrayref is enabled. decode_hv() collapses duplicate object keys into an array reference under dupkeys_as_arrayref. The branch re

Q: How urgent is CVE-2026-9334?

Priority 35/100. High severity; Remotely exploitable, no login, no user action

Routine

HIGH 7.3REMOTEUPGRADE

CVE-2026-9334 is a high-severity flaw (CVSS 7.3) affecting cpanel\. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Cpanel::JSON::XS versions before 4.41 for Perl allow type confusion via duplicate object keys when dupkeys_as_arrayref is enabled. decode_hv() collapses duplicate object keys into an array reference under dupkeys_as_arrayref. The branch reached for a duplicate key tests `SvTYPE (old_value) != SVt_RV && SvTYPE (SvRV (old_value)) != SVt_PVAV`, which evaluates SvRV(old_value) before establishing that old_value is a reference. When the existing valu

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.3 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 83%)
CISA exploited list	No
Weakness	CWE-843
Published	2026-06-03
Last modified	2026-07-21

Publisher (CNA): CPANSec · Vendor: rurban

Last updated 2026-07-21 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-03 01:16 UTCPublished CVE record published
2026-07-21 19:10 UTCUpdated Record last modified

rurban cpanel\ UPGRADE

Affected: < 4.41

Fixed in: 4.41

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 4.41 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade cpanel

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-2026-9334?

cpanel\: upgrade to 4.41. Exact commands for each OS are on this page.

Is CVE-2026-9334 being exploited?

CVE-2026-9334 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-2026-9334 affect?

CVE-2026-9334 affects cpanel\. Severity is high (CVSS 7.3). Cpanel::JSON::XS versions before 4.41 for Perl allow type confusion via duplicate object keys when dupkeys_as_arrayref is enabled. decode_hv() collapses duplicate object keys into an array reference under dupkeys_as_arrayref. The branch re

How urgent is CVE-2026-9334?

Priority 35/100. High severity; Remotely exploitable, no login, no user action

Software pages

Perl vulnerabilities

Related CVEs

CVE-2026-9516 HIGH 7.5 UPGRADE Cpanel::JSON::XS versions before 4.41 for Perl allow denial of service via UTF-8 BOM prefixed input when a dec

References

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