CPANSA-Cpanel-JSON-XS-2026-110688: Cpanel-JSON-XS vulnerability
| Publisher | giterlizzi | Document category | csaf_security_advisory |
|---|---|---|---|
| Initial release date | 2026-10-19T00:00:00 | Engine | CSAF Perl Toolkit 0.26 |
| Current release date | 2026-10-19T00:00:00 | Build Date | |
| Current version | 1 | Status | final |
| CVSS v3.1 Base Score | 7.5 | Severity | High |
| Original language | Language | en | |
| Also referred to | |||
Vulnerability Description
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.
Vulnerabilities
CVE-2026-110688
Vulnerability DescriptionCpanel::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.
| Weakness | CWE-407 : Inefficient Algorithmic Complexity |
|---|
Product status
Known affected
| Product | Score | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Cpanel-JSON-XS greater than or equal 4.51 and less than 4.80 |
|
Fixed
- Cpanel-JSON-XS greater than or equal 4.80
giterlizzi
Namespace: https://github.com/giterlizzi/
gdt@cpan.org
References
- CPANSA-Cpanel-JSON-XS-2026-110688 JSON self
https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2026/cpansa-cpanel-json-xs-2026-110688.json - https://github.com/rurban/Cpanel-JSON-XS/commit/384309f6a297384e69c851b5d64e1c421d9b2dcc.patch external
https://github.com/rurban/Cpanel-JSON-XS/commit/384309f6a297384e69c851b5d64e1c421d9b2dcc.patch - https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.80/changes external
https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.80/changes - CVE-2026-110688 (NVD) external
https://nvd.nist.gov/vuln/detail/CVE-2026-110688
Revision history
| Version | Date of the revision | Summary of the revision |
|---|---|---|
| 1 | Mon Oct 19 00:00:00 2026 | First release |
Sharing rules
TLP:WHITE
For the TLP version see: https://www.first.org/tlp/