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.
CVE-2026-110686
CVSS base score
6.5 (v3.1)
Severity
MEDIUM
Attack vector
Network
Weakness
CWE-416
Last modified
October 29, 2026
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H