Cpanel::JSON::XS versions before 4.41 for Perl allow type confusion via duplicate object keys when dupkeys_as_arrayref is enabled

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-9334
StatePUBLISHED
AssignerCPANSec
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-03 01:16:23 UTC
Updated2026-06-05 17:36:29 UTC
DescriptionCpanel::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 value is a plain scalar rather than an array reference, a non-reference scalar is dereferenced as a reference. A caller decoding untrusted JSON with dupkeys_as_arrayref enabled is crashed, and the incompatible access follows a pointer taken from attacker controlled scalar contents.

Risk And Classification

Primary CVSS: v3.1 7.3 HIGH from ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

EPSS: 0.000480000 probability, percentile 0.154000000 (date 2026-06-10)

Problem Types: CWE-843 | CWE-843 CWE-843 Access of Resource Using Incompatible Type ('Type Confusion')

VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED7.3HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary7.3HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Rurban Cpanel \ json\ \ xs

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA RURBAN CpanelJSONXS affected 4.41 custom Not specified

References

ReferenceSourceLinkTags
metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.41/changes 9b29abf9-4ab0-4765-b253-1875cd9b441e metacpan.org Release Notes
github.com/rurban/Cpanel-JSON-XS/commit/11a7c550a0d8fac2f84414f24d5df9b2... 9b29abf9-4ab0-4765-b253-1875cd9b441e github.com Patch
www.openwall.com/lists/oss-security/2026/06/03/4 af854a3a-2127-422b-91ae-364da2661108 www.openwall.com Mailing List, Third Party Advisory, Patch
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

SourceTimeEvent
CNA2026-02-24T00:00:00.000ZIssue reported.
CNA2026-05-27T00:00:00.000ZVersion 4.41 released with fix.
CNA2026-05-28T00:00:00.000ZFix verified.

Solutions

CNA: Upgrade to Cpanel::JSON::XS 4.41 or later.

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