Vulnerability · Published Sep 8, 2025 · Assigned by CPANSec
CVE-2025-40929Cpanel::JSON::XS before version 4.40 for Perl has an integer buffer overflow causing a segfault when parsing crafted JSON, enabling denial-of-service attacks or other unspecified impact
Medium 5.6
In plain English
A medium-severity heap buffer overflow in Cpanel::JSON::XS from RURBAN. 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 40% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)5.6Medium
Exploit odds (30 days)0.5%top 60.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Cpanel::JSON::XS before version 4.40 for Perl has an integer buffer overflow causing a segfault when parsing crafted JSON, enabling denial-of-service attacks or other unspecified impact
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | perl-cpanel-json-xs | 4.40-r0 | ALPINE-CVE-2025-40929 |
| Alpine:v3.21 | perl-cpanel-json-xs | 4.40-r0 | ALPINE-CVE-2025-40929 |
| Alpine:v3.22 | perl-cpanel-json-xs | 4.40-r0 | ALPINE-CVE-2025-40929 |
| Alpine:v3.23 | perl-cpanel-json-xs | 4.40-r0 | ALPINE-CVE-2025-40929 |
| Alpine:v3.24 | perl-cpanel-json-xs | 4.40-r0 | ALPINE-CVE-2025-40929 |
| Debian:12 | libcpanel-json-xs-perl | 4.35-1+deb12u1 | DSA-6000-1 |
| Debian:12 | libcpanel-json-xs-perl | 4.35-1+deb12u1 | DEBIAN-CVE-2025-40929 |
| Debian:13 | libcpanel-json-xs-perl | 4.39-2~deb13u1 | DEBIAN-CVE-2025-40929 |
| Debian:13 | libcpanel-json-xs-perl | 4.39-2~deb13u1 | DSA-6000-1 |
| Debian:14 | libcpanel-json-xs-perl | 4.39-2 | DEBIAN-CVE-2025-40929 |
| Ubuntu:22.04:LTS | libcpanel-json-xs-perl | 4.27-1ubuntu0.2 | USN-7749-1 |
| Ubuntu:22.04:LTS | libcpanel-json-xs-perl | 4.27-1ubuntu0.2 | UBUNTU-CVE-2025-40929 |
| Ubuntu:24.04:LTS | libcpanel-json-xs-perl | 4.37-1ubuntu0.1 | UBUNTU-CVE-2025-40929 |
| Ubuntu:24.04:LTS | libcpanel-json-xs-perl | 4.37-1ubuntu0.1 | USN-7749-1 |
| Ubuntu:25.10 | libcpanel-json-xs-perl | 4.39-2 | UBUNTU-CVE-2025-40929 |
| Ubuntu:26.04:LTS | libcpanel-json-xs-perl | 4.39-2 | UBUNTU-CVE-2025-40929 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| RURBAN | Cpanel::JSON::XS | 0 – before 4.40 |
Weakness: CWE-122 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
References
- https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.39/source/XS.xs#L713 related
- https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.40/changes release-notes
- https://github.com/rurban/Cpanel-JSON-XS/commit/378236219eaa35742c3962ecbdee364903b0a1f2.patch patch
- https://lists.debian.org/debian-lts-announce/2025/09/msg00034.html
- http://www.openwall.com/lists/oss-security/2025/09/08/1