Bug 2556487

Summary: CVE-2026-110687 perl-Cpanel-JSON-XS: Incorrect canonical sorting of byte-string keys in utf16_cmp [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": ["55bf5ce0-af17-45f0-8743-69db70a71b06"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2555770    

Description Guilherme de Almeida Suckevicz 2026-10-20 20:52:34 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 4.43 before 4.80 for Perl misorder byte-string keys during canonical encoding in utf16_cmp.

canonical sorts keys by UTF-16 code units. When any key in a hash is UTF-8 flagged, every key is decoded as UTF-8 for the comparison, including byte-string keys that the encoder writes out as Latin-1 characters. A byte-string key whose bytes are valid UTF-8 is sorted out of order, and two keys that encode differently can compare equal and are left in hash order.

The same data can encode to different canonical documents across processes.

Comment 1 Fedora Update System 2026-10-21 09:13:26 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 09:16:09 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 09:18:50 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