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Vulnerability · Published Oct 19, 2026 · Assigned by CPANSec

CVE-2026-110681Cpanel::JSON::XS versions before 4.80 for Perl use the parent interpreter's scalars from a parser object cloned into a new ithread

High 8.1

In plain English

A high-severity use-after-free in Cpanel-JSON-XS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.4%top 62.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Cpanel::JSON::XS versions before 4.80 for Perl use the parent interpreter's scalars from a parser object cloned into a new ithread. A parser object holds its callbacks and its incremental parse buffer as raw scalar pointers. When a thread is created, these are copied into the new interpreter unchanged, so the child's parser uses, and later frees, scalars that belong to the parent and may already have been freed there. A parser created before a thread starts and used inside it can call freed callbacks, corrupt reference counts and crash the process.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12libcpanel-json-xs-perlno fix listedDEBIAN-CVE-2026-110681
Debian:13libcpanel-json-xs-perlno fix listedDEBIAN-CVE-2026-110681
Debian:14libcpanel-json-xs-perl4.80-1DEBIAN-CVE-2026-110681
Ubuntu:22.04:LTSlibcpanel-json-xs-perlno fix listedUBUNTU-CVE-2026-110681
Ubuntu:24.04:LTSlibcpanel-json-xs-perlno fix listedUBUNTU-CVE-2026-110681
Ubuntu:26.04:LTSlibcpanel-json-xs-perlno fix listedUBUNTU-CVE-2026-110681
Ubuntu:26.10libcpanel-json-xs-perlno fix listedUBUNTU-CVE-2026-110681

Affected products (as reported)

VendorProductVersions
Cpanel-JSON-XS 0 – before 4.80

Weakness: CWE-416 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

References