CVE-2026-9334
Cpanel::JSON::XS versions before 4.41 for Perl allow type confusion via duplicate object keys when dupkeys_as_arrayref is enabled
Description
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 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.
INFO
Published Date :
June 3, 2026, 1:16 a.m.
Last Modified :
June 5, 2026, 5:36 p.m.
Remotely Exploit :
Yes !
Source :
9b29abf9-4ab0-4765-b253-1875cd9b441e
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update Cpanel::JSON::XS to version 4.41 or later.
- Ensure JSON parsing handles duplicate keys securely.
- Avoid decoding untrusted JSON with specific settings.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-9334.
| URL | Resource |
|---|---|
| https://github.com/rurban/Cpanel-JSON-XS/commit/11a7c550a0d8fac2f84414f24d5df9b2bfe346e2.patch | Patch |
| https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.41/changes | Release Notes |
| http://www.openwall.com/lists/oss-security/2026/06/03/4 | Mailing List Third Party Advisory Patch |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-9334 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-9334
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-9334 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-9334 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 05, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:rurban:cpanel::json::xs:*:*:*:*:*:perl:*:* versions up to (excluding) 4.41 Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/06/03/4 Types: Mailing List, Patch, Third Party Advisory Added Reference Type CPANSec: https://github.com/rurban/Cpanel-JSON-XS/commit/11a7c550a0d8fac2f84414f24d5df9b2bfe346e2.patch Types: Patch Added Reference Type CPANSec: https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.41/changes Types: Release Notes -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 03, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Jun. 03, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/06/03/4 -
New CVE Received by 9b29abf9-4ab0-4765-b253-1875cd9b441e
Jun. 03, 2026
Action Type Old Value New Value Added Description 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 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. Added CWE CWE-843 Added Reference https://github.com/rurban/Cpanel-JSON-XS/commit/11a7c550a0d8fac2f84414f24d5df9b2bfe346e2.patch Added Reference https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.41/changes