Description
Cpanel::JSON::XS versions from 4.42 before 4.80 for Perl let input chunking change the decoded value of top-level numbers in incr_parse. allow_nonref is enabled by default and incr_parse inherits it. A top-level number, true, false or null has no closing delimiter, so the incremental parser decodes whatever has arrived. The bytes 12 decode as one value when read together, but as 1 and then 2 when split across two reads. A peer that can influence read boundaries can change how many messages a stream consumer decodes and what values they carry.
References2
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - EPSS — exploit probability
- 0% percentile: 37 · as of 10 November 2026
- CWE
- CWE-436
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