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Fencer Vulns
high 7.5

CVE-2026-9516 json

Cpanel::JSON::XS versions before 4.41 for Perl allow denial of service via UTF-8 BOM prefixed input when a decode filter callback throws

published 2026-06-03 5 mo ago modified 2026-07-22 3 mo ago also EUVD-2026-34061

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

Cpanel::JSON::XS versions before 4.41 for Perl allow denial of service via UTF-8 BOM prefixed input when a decode filter callback throws.

To skip a leading 3-byte UTF-8 BOM, decode_json() advances the input scalar's string pointer past the mark with SvPV_set() and restores it only on the normal return path. When decoding aborts through a Perl exception, for example a filter_json_object callback that croaks, the restore is skipped and the scalar is left with its string pointer offset into its own buffer and a shortened length.

When that scalar is later freed, the allocator receives an invalid pointer and the interpreter aborts. A single BOM prefixed document decoded with a throwing filter callback crashes any caller.

Patch / fix

  • RURBAN Cpanel::JSON::XS 4.41
  • libcpanel-json-xs-perl Debian 14 4.41-1

debian advisories DEBIAN-CVE-2026-9516

  • perl-Cpanel-JSON-XS SLE Module for Package Hub 15 SP7 4.800.0-150700.3.9.1
  • perl-Cpanel-JSON-XS SLE Module for Package Hub 15 SP7 4.380.0-150700.3.6.1

suse advisories SUSE-SU-2026:4926-1SUSE-SU-2026:2782-1

  • perl-Cpanel-JSON-XS openSUSE Leap 16.0 4.420.0-bp160.1.1
  • perl-Cpanel-JSON-XS openSUSE Tumbleweed 4.410.0-1.1

opensuse advisories openSUSE-SU-2026:21140-1openSUSE-SU-2026:10950-1

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-2026-9516 updated cvss 7.5

perl-Cpanel-JSON-XS: Cpanel::JSON::XS: Denial of Service via UTF-8 BOM prefixed input

  • 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
5 mo ago

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 30% 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

Affected products

  • RURBAN Cpanel::JSON::XS

Classification

Weakness
  • CWE-763 Release of Invalid Pointer or Reference
  • CWE-755 Improper Handling of Exceptional Conditions

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.