What’s Vulnerable › Vulnerabilities

CVE-2025-40929: 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

• Severity: medium (CVSS 5.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-09-08 · updated 2026-06-17
• Weakness: CWE-122

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 products

• RURBAN Cpanel::JSON::XS: before 4.40 — fixed in 4.40

How to fix

Upgrade to a fixed version: RURBAN Cpanel::JSON::XS 4.40. Check the vendor advisory for mitigations.

References

• https://github.com/rurban/Cpanel-JSON-XS/commit/378236219eaa35742c3962ecbdee364903b0a1f2.patch
• https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.39/source/XS.xs#L713
• https://metacpan.org/release/RURBAN/Cpanel-JSON-XS-4.40/changes
• http://www.openwall.com/lists/oss-security/2025/09/08/1
• https://lists.debian.org/debian-lts-announce/2025/09/msg00034.html

Get alerted when CVE-2025-40929 or the next vulnerability affects your stack