---
id: CVE-2026-110688
title: >-
  Cpanel::JSON::XS versions from 4.51 before 4.80 for Perl allow quadratic CPU
  use by revalidating the remaining buffer per value in incr_parse
summary: >-
  Cpanel::JSON::XS versions from 4.51 before 4.80 for Perl allow quadratic CPU
  use by revalidating the remaining buffer per value in incr_parse.


  At the first non-ASCII byte in a string, the decoder validates UTF-8 from
  there to the end of…
severity: none
cwe:
  - CWE-407
product: Cpanel-JSON-XS
affected:
  - Cpanel-JSON-XS >= 4.51 < 4.80
published: '2026-10-19'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T18:12:25.276Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-110688'
references:
  - url: >-
      https://github.com/rurban/Cpanel-JSON-XS/commit/384309f6a297384e69c851b5d64e1c421d9b2dcc.patch
  - url: 'https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.80/changes'
tags:
  - cve.org
ingestedAt: '2026-10-19T18:35:50.141Z'
---

## Overview

Cpanel::JSON::XS versions from 4.51 before 4.80 for Perl allow quadratic CPU use by revalidating the remaining buffer per value in incr_parse.

At the first non-ASCII byte in a string, the decoder validates UTF-8 from there to the end of its input. incr_parse decodes each buffered value with a fresh decoder, so every value revalidates the rest of the buffer, and doubling the input quadruples the work.

A peer that sends about a megabyte of ordinary non-ASCII JSON in one read ties up the process for seconds of CPU time.

## Affected

- `Cpanel-JSON-XS >= 4.51 < 4.80`

## Remediation

Upgrade to Cpanel-JSON-XS 4.80 or later.