CVE-2026-110686
Received Received - Intake

Heap Overflow in Cpanel::JSON::XS Perl Module

Vulnerability report for CVE-2026-110686, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-10-19

Last updated on: 2026-10-19

Assigner: CPANSec

Description

Cpanel::JSON::XS versions before 4.80 for Perl use freed filter callbacks when a filter removes itself during decoding in decode_hv. A decode copies the parser's filter_json_object and filter_json_single_key_object callbacks without taking references to them. A filter callback that removes the last single-key filter frees the callback table while the decode in progress still uses it. The next object is dispatched through freed memory and can crash the process.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-10-19
Last Modified
2026-10-19
Generated
2026-10-19
AI Q&A
2026-10-19
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
cpanel json_xs to 4.80 (exc)
rurban cpanel_json_xs to 4.80 (exc)

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-416 The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

CVE-2026-110686 is a use-after-free vulnerability in Cpanel::JSON::XS versions before 4.80 for Perl. It occurs when a filter callback removes itself during JSON decoding. The decode operation copies filter callbacks without proper references, leading to freed memory being used again. This can crash the process due to memory corruption.

Detection Guidance

To detect this vulnerability, check the version of Cpanel::JSON::XS installed on your system. If it is below 4.80, the system is vulnerable. Run: perl -MCpanel::JSON::XS -e 'print $Cpanel::JSON::XS::VERSION' to check the version.

Impact Analysis

This vulnerability can cause application crashes or unexpected behavior when processing JSON data with self-removing filter callbacks. It may lead to denial-of-service conditions or potential arbitrary code execution if exploited maliciously.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR or HIPAA as it pertains to memory corruption in a Perl JSON decoding module. However, if exploited, it could lead to application crashes or undefined behavior, potentially causing data processing failures that might indirectly impact compliance.

Mitigation Strategies

Immediately update Cpanel::JSON::XS to version 4.80 or later. If updating is not possible, remove or disable any JSON decoding filters that may trigger the use-after-free issue until the update is applied.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-110686. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart