CPANSA-Cpanel-JSON-XS-2026-110685: 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 9.1 Severity Critical
Original language Language en
Also referred to

Vulnerability Description

Cpanel::JSON::XS versions before 4.80 for Perl leak the decoded arguments of a tagged value when its THAW method dies in decode_tag.

With allow_tags, a tagged value's class name and argument array are decoded and passed to the class's THAW method. Both are released only after THAW returns, so a THAW that dies leaves the whole decoded argument structure allocated.

Each rejected document leaks data of a size the sender chooses, so a process that catches the error and keeps running exhausts its memory.

Vulnerabilities

CVE-2026-110685

Vulnerability Description

Cpanel::JSON::XS versions before 4.80 for Perl leak the decoded arguments of a tagged value when its THAW method dies in decode_tag.

With allow_tags, a tagged value's class name and argument array are decoded and passed to the class's THAW method. Both are released only after THAW returns, so a THAW that dies leaves the whole decoded argument structure allocated.

Each rejected document leaks data of a size the sender chooses, so a process that catches the error and keeps running exhausts its memory.

Weakness CWE-401 : Missing Release of Memory after Effective Lifetime

Product status

Known affected
Product Score
Cpanel-JSON-XS less than 4.80
CVSS Version CVSS Vector CVSS Base Score CVSS Base Severity
3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H 9.1 Critical
Fixed

giterlizzi

Namespace: https://github.com/giterlizzi/

gdt@cpan.org

References

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/