CPANSA-Cpanel-JSON-XS-2026-110687: Cpanel-JSON-XS vulnerability

Publisher giterlizzi Document category csaf_security_advisory
Initial release date 2026-10-19T00:00:00 Engine CSAF Perl Toolkit 0.26
Current release date 2026-10-19T00:00:00 Build Date
Current version 1 Status final
CVSS v3.1 Base Score 7.5 Severity High
Original language Language en
Also referred to

Vulnerability Description

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.

Vulnerabilities

CVE-2026-110687

Vulnerability Description

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.

Weakness CWE-176 : Improper Handling of Unicode Encoding

Product status

Known affected
Product Score
Cpanel-JSON-XS greater than or equal 4.43 and less than 4.80
CVSS Version CVSS Vector CVSS Base Score CVSS Base Severity
3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N 7.5 High
Fixed

giterlizzi

Namespace: https://github.com/giterlizzi/

gdt@cpan.org

References

Revision history

Version Date of the revision Summary of the revision
1 Mon Oct 19 00:00:00 2026 First release

Sharing rules

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