Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by buffering incremental input past max_size in incr_parse.

The parser appends each chunk to its buffer. In scalar or list context, it compares max_size with how far it has progressed, not with the buffer length. A chunk that starts with a NUL byte stops the parser before it progresses, and a call in void context skips the check, so the buffer grows without limit.

A peer streaming data to an incr_parse consumer can exhaust process memory regardless of max_size.

Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by buffering incremental input past max_size in incr_parse.

The parser appends each chunk to its buffer. In scalar or list context, it compares max_size with how far it has progressed, not with the buffer length. A chunk that starts with a NUL byte stops the parser before it progresses, and a call in void context skips the check, so the buffer grows without limit.

A peer streaming data to an incr_parse consumer can exhaust process memory regardless of max_size.

perl-Cpanel-JSON-XS-4.800.0-1.1 on GA media

Affected: Ubuntu:16.04:LTS: libcpanel-json-xs-perl, Ubuntu:18.04:LTS: libcpanel-json-xs-perl, Ubuntu:20.04:LTS: libcpanel-json-xs-perl, Ubuntu:22.04:LTS: libcpanel-json-xs-perl, Ubuntu:24.04:LTS: libcpanel-json-xs-perl, Ubuntu:26.10: libcpanel-json-xs-perl, Ubuntu:26.04:LTS: libcpanel-json-xs-perl

(Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion ...)