CVE-2026-9334Network attack vector

Application crash via duplicate-key type confusion

Published Jun 3, 2026 · Updated Jun 3, 2026

Type confusion in Cpanel::JSON::XS before 4.41 allows remote attackers to crash applications via crafted JSON with duplicate object keys. In decode_hv, a per-decode flag is cleared after wrapping the first repeated key, and an AND condition then lets SvRV dereference a scalar for a second distinct repeated key. The vulnerable path requires dupkeys_as_arrayref to be enabled and at least two distinct duplicated keys; triggering it terminates the decoding Perl process.

CVSS severity7.3
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Type confusion in Cpanel::JSON::XS before 4.41 allows remote attackers to crash applications via crafted JSON with duplicate object keys. In decode_hv, a per-decode flag is cleared after wrapping the first repeated key, and an AND condition then lets SvRV dereference a scalar for a second distinct repeated key. The vulnerable path requires dupkeys_as_arrayref to be enabled and at least two distinct duplicated keys; triggering it terminates the decoding Perl process.

The record

CVE
CVE-2026-9334
Published
Jun 3, 2026
Updated
Jun 3, 2026
Vendor
Reini Urban
Product
Cpanel::JSON::XS
Classifications
CWE-843, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=0 <4.41

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Reini Urban · Cpanel::JSON::XSversion=0 <4.41

Published CVSS scores

7.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-843Access of Resource Using Incompatible Type ('Type Confusion')
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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