CVE-2026-110676

Publication date 19 October 2026

Last updated 13 November 2026

Ubuntu priority

Cvss 3 Severity Score

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.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
libcpanel-json-xs-perl	26.10 stonking	Vulnerable
	26.04 LTS resolute	Vulnerable
	24.04 LTS noble	Vulnerable
	22.04 LTS jammy	Vulnerable
	20.04 LTS focal	Vulnerable
	18.04 LTS bionic	Vulnerable
	16.04 LTS xenial	Vulnerable

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
libcpanel-json-xs-perl	Upstream: 996ab96

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.5 · High

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	None
Availability impact	High

Scores

Parameter	Value
Base score	7.5 · High
Exploitability score	-
Impact score	-

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H