Bug 2556488

Summary: CVE-2026-110684 perl-Cpanel-JSON-XS: Memory leak in encode_stringify when encoding overloaded objects [fedora-all]
Product: [Fedora] Fedora Reporter: Guilherme de Almeida Suckevicz <gsuckevi>
Component: perl-Cpanel-JSON-XSAssignee: Paul Howarth <paul>
Status: MODIFIED --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: paul, perl-devel
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["090cd7ad-8d6b-4074-a990-1ce946e5e00d"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Blocks: 2555771    

Description Guilherme de Almeida Suckevicz 2026-10-20 20:52:55 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

Cpanel::JSON::XS versions from 3.0202 before 4.80 for Perl leak memory and retain overloaded objects when encoding values as strings in encode_stringify.

encode_stringify writes a value in its string form under allow_stringify, under convert_blessed for objects without TO_JSON, and under allow_bignum. For an array or hash object with a "" overload, and from 4.20 a scalar object, it takes an extra reference that is never released, so the object and everything it references are never freed. From 4.10 it also never frees its copy of the string.

Repeatedly encoding data that contains such values grows process memory without bound.

Comment 1 Fedora Update System 2026-10-21 09:13:29 UTC
FEDORA-2026-ad8dfeadc9 (perl-Cpanel-JSON-XS-4.80-1.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-ad8dfeadc9

Comment 2 Fedora Update System 2026-10-21 09:16:11 UTC
FEDORA-2026-3ab4727120 (perl-Cpanel-JSON-XS-4.80-1.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-3ab4727120

Comment 3 Fedora Update System 2026-10-21 09:18:53 UTC
FEDORA-2026-4447e52d23 (perl-Cpanel-JSON-XS-4.80-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-4447e52d23