Vulnerability · Published Oct 19, 2026 · Assigned by CPANSec
CVE-2026-110674Cpanel::JSON::XS versions from 4.33 before 4.80 for Perl miss duplicate non-ASCII bare keys, allowing type confusion under dupkeys_as_arrayref in decode_hv
Medium 6.5
In plain English
A medium-severity type confusion in Cpanel-JSON-XS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Cpanel::JSON::XS versions from 4.33 before 4.80 for Perl miss duplicate non-ASCII bare keys, allowing type confusion under dupkeys_as_arrayref in decode_hv. With allow_barekey, which relaxed enables, a bare key containing a non-ASCII byte is stored as UTF-8 but looked up as raw bytes, so a repeated key escapes the duplicate-key check and replaces the earlier value. From 4.41, under dupkeys_as_arrayref, a bare repeat replaces the array that collects a key's values with a plain value, and the next quoted repeat pushes onto that value as if it were an array. A JSON integer there is dereferenced as a pointer. Untrusted JSON decoded with relaxed and dupkeys_as_arrayref can crash the process or dereference an address chosen by a JSON number.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libcpanel-json-xs-perl | no fix listed | DEBIAN-CVE-2026-110674 |
| Debian:13 | libcpanel-json-xs-perl | no fix listed | DEBIAN-CVE-2026-110674 |
| Debian:14 | libcpanel-json-xs-perl | 4.80-1 | DEBIAN-CVE-2026-110674 |
| Ubuntu:22.04:LTS | libcpanel-json-xs-perl | no fix listed | UBUNTU-CVE-2026-110674 |
| Ubuntu:24.04:LTS | libcpanel-json-xs-perl | no fix listed | UBUNTU-CVE-2026-110674 |
| Ubuntu:26.04:LTS | libcpanel-json-xs-perl | no fix listed | UBUNTU-CVE-2026-110674 |
| Ubuntu:26.10 | libcpanel-json-xs-perl | no fix listed | UBUNTU-CVE-2026-110674 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cpanel-JSON-XS | 4.33 – before 4.80 |
Weakness: CWE-843, CWE-176 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H