CVE-2026-9334

high

Published 2026-06-03 · Modified 2026-06-03

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CVSS v3

7.3

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

CVSS v4 NEW

—

not yet in upstream

VIR risk

7.3

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.

Predictions

Exploit likelihood

82%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

Mitigation details

Source: Debian Security Tracker · View original ↗ · DFSG

CVE-2026-9334 NameCVE-2026-9334 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…

CVE-2026-9334

Name	CVE-2026-9334
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1138273

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
libcpanel-json-xs-perl (PTS)	bullseye	4.25-1	vulnerable
	bullseye (security)	4.25-1+deb11u1	vulnerable
	bookworm, bookworm (security)	4.35-1+deb12u1	vulnerable
	trixie (security), trixie	4.39-2~deb13u1	vulnerable
	forky, sid	4.41-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
libcpanel-json-xs-perl	source	(unstable)	4.41-1			1138273

Notes

[trixie] - libcpanel-json-xs-perl <no-dsa> (Minor issue)
[bookworm] - libcpanel-json-xs-perl <no-dsa> (Minor issue)
Fixed by: https://github.com/rurban/Cpanel-JSON-XS/commit/11a7c550a0d8fac2f84414f24d5df9b2bfe346e2 (4.41)

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Apply commands

text fix

Notes

[trixie] - libcpanel-json-xs-perl <no-dsa> (Minor issue)[bookworm] - libcpanel-json-xs-perl <no-dsa> (Minor issue)Fixed by: https://github.com/rurban/Cpanel-JSON-XS/commit/11a7c550a0d8fac2f84414f24d5df9b2bfe346e2 (4.41)

OS impact

SUSE Affected 1 release

Version	Status	Fixed in
—	Affected	—

Debian Mixed 5 releases

Version	Status	Fixed in
trixie	Affected	—
sid	Fixed	`4.41-1`
forky	Fixed	`4.41-1`
bullseye	Affected	—
bookworm	Affected	—

References

CWEs

CWE-843

Community-verified mitigations for this CVE will appear above when contributors publish them.

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