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Vulnerability · Published Oct 19, 2026 · Assigned by CPANSec

CVE-2026-110686Cpanel::JSON::XS versions before 4.80 for Perl use freed filter callbacks when a filter removes itself during decoding in decode_hv

Medium 6.5

In plain English

A medium-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 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.4%top 62.2% 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 freed filter callbacks when a filter removes itself during decoding in decode_hv. A decode copies the parser's filter_json_object and filter_json_single_key_object callbacks without taking references to them. A filter callback that removes the last single-key filter frees the callback table while the decode in progress still uses it. The next object is dispatched through freed memory and can crash the process.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12libcpanel-json-xs-perlno fix listedDEBIAN-CVE-2026-110686
Debian:13libcpanel-json-xs-perlno fix listedDEBIAN-CVE-2026-110686
Debian:14libcpanel-json-xs-perl4.80-1DEBIAN-CVE-2026-110686
Ubuntu:22.04:LTSlibcpanel-json-xs-perlno fix listedUBUNTU-CVE-2026-110686
Ubuntu:24.04:LTSlibcpanel-json-xs-perlno fix listedUBUNTU-CVE-2026-110686
Ubuntu:26.04:LTSlibcpanel-json-xs-perlno fix listedUBUNTU-CVE-2026-110686
Ubuntu:26.10libcpanel-json-xs-perlno fix listedUBUNTU-CVE-2026-110686

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:N/A:H

References