Description
Cpanel::JSON::XS versions from 4.28 before 4.80 for Perl leak the array collecting duplicate key values under dupkeys_as_arrayref in decode_hv.
With dupkeys_as_arrayref, the values of a duplicate object key are collected into a new array. An extra reference is never released, so the array and every value in it outlive the decoded structure. The array also leaks when decoding fails after a duplicate key.
Repeatedly decoding untrusted JSON with a duplicate key holding a large value exhausts process memory.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | Cpanel-JSON-XS | 4.28 – < 4.80 | 4.80 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libcpanel-json-xs-perl | 4.80-1 | — |
| Debian 13 | libcpanel-json-xs-perl | No fix yet | — |
| Debian 12 | libcpanel-json-xs-perl | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libcpanel-json-xs-perl | No fix yet | — |
| Ubuntu 26.04 LTS | libcpanel-json-xs-perl | No fix yet | — |
| Ubuntu 24.04 LTS | libcpanel-json-xs-perl | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | perl-Cpanel-JSON-XS | 4.800.0-150700.3.9.1 | SUSE-SU-2026:4926-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | perl-Cpanel-JSON-XS | 4.800.0-1.1 | openSUSE-SU-2026:12217-1 |
| openSUSE Leap 16.0 | perl-Cpanel-JSON-XS | 4.800.0-bp160.1.1 | openSUSE-SU-2026:22187-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | perl-Cpanel-JSON-XS | No fix yet | — |
Advisories 3
- openSUSE-SU-2026:22187-1 Security update for perl-Cpanel-JSON-XS SUSE / openSUSE Security Updates · Nov 1, 2026
- SUSE-SU-2026:4926-1 Security update for perl-Cpanel-JSON-XS SUSE / openSUSE Security Updates · Oct 29, 2026
- openSUSE-SU-2026:12217-1 perl-Cpanel-JSON-XS-4.800.0-1.1 on GA media SUSE / openSUSE Security Updates · Oct 22, 2026