Bug 2556464

Summary: CVE-2026-110673 perl-Cpanel-JSON-XS: Stack exhaustion via nested tagged values under allow_tags [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
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["4ca4fc7b-013b-4216-935a-0be2b066b366"]}
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2555755    

Description Guilherme de Almeida Suckevicz 2026-10-20 20:47:53 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 before 4.80 for Perl allow stack exhaustion via nested tagged values under allow_tags in decode_tag.

With allow_tags, "(" starts a tagged value. Its tag and value are decoded recursively, and each can start another tagged value. Unlike arrays and objects, this nesting is not counted against max_depth.

A run of "(" bytes exhausts the C stack and triggers an uncatchable segmentation fault regardless of max_depth.

Comment 1 Fedora Update System 2026-10-21 09:12:53 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 09:15:37 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 09:18:21 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