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Fencer Vulns
high 7.5

CVE-2026-110688 json

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

published 2026-10-19 20 d ago modified 2026-10-29 10 d ago also EUVD-2026-104567

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 42%
public exploits
0
none known

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 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.

Patch / fix

  • rurban cpanel-json-xs 4.80
  • libcpanel-json-xs-perl Debian 14 4.80-1

debian advisories DEBIAN-CVE-2026-110688

  • perl-Cpanel-JSON-XS SLE Module for Package Hub 15 SP7 4.800.0-150700.3.9.1

suse advisories SUSE-SU-2026:4926-1

  • perl-Cpanel-JSON-XS openSUSE Leap 16.0 4.800.0-bp160.1.1
  • perl-Cpanel-JSON-XS openSUSE Tumbleweed 4.800.0-1.1

opensuse advisories openSUSE-SU-2026:22187-1openSUSE-SU-2026:12217-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-110688 updated cvss 7.5

perl-Cpanel-JSON-XS: Quadratic CPU usage in incr_parse

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
10 d ago

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Classification

Weakness
  • CWE-407 Inefficient Algorithmic Complexity

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.