CVE-2026-110676

Name	CVE-2026-110676
Description	Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by encoding exponent notation as full decimal digits under allow_bignum. With allow_bignum, a JSON number with a fraction or exponent decodes to a Math::BigFloat, which stores the exponent separately and so decodes cheaply. Encoding it untyped or as JSON_TYPE_FLOAT writes the plain decimal form with one digit per unit of exponent. Nothing bounds the exponent, so the 12-byte text [1e30000000] encodes to 30 MB. Untrusted JSON decoded with allow_bignum and encoded again can exhaust memory and CPU.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
libcpanel-json-xs-perl (PTS)	bookworm, bookworm (security)	4.35-1+deb12u1	vulnerable
	trixie (security), trixie	4.39-2~deb13u1	vulnerable
	forky	4.51-1	vulnerable
	sid	4.80-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
libcpanel-json-xs-perl	source	(unstable)	4.80-1

Notes

https://lists.security.metacpan.org/cve-announce/msg/44479732/
Fixed by: https://github.com/rurban/Cpanel-JSON-XS/commit/996ab96972b967a917536d291947b5f3cf42e960 (4.80)