Check Point Advisories

Linux Kernel Denial of Service (CVE-2025-21758)

Vulnerability
Protection

Check Point Reference:	CPAI-2025-13454
Date Published:	23 Mar 2026
Severity:	Medium
Last Updated:	Monday 23 March, 2026
Source:
Industry Reference:	CVE-2025-21758
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	Linux Kernel 2.6.26 and later, prior to 5.15.179 Linux Kernel 5.16 and later, prior to 6.1.129 Linux Kernel 6.2 and later, prior to 6.6.79 Linux Kernel 6.7 and later, prior to 6.12.16 Linux Kernel 6.13 and later, prior to 6.13.4 Linux Kernel 6.14 rc1 Linux Kernel 6.14 rc2
Vulnerability Description	A denial of service vulnerability in Linux Kernel allows attackers to cause a denial-of-service condition by exploiting the mld_newpack() function, which can be called without RTNL or RCU being held. This issue arises due to the use of GFP_KERNEL allocations that can sleep, leading to potential system instability.

Protection Overview

This protection detects attempts to exploit this vulnerability.

In order for the protection to be activated, update your Security Gateway product to the latest IPS update. For information on how to update IPS, go to SBP-2006-05, click on Protection tab and select the version of your choice.

Security Gateway R81 / R80 / R77 / R75

In the IPS tab, click Protections and find the Linux Kernel Denial of Service (CVE-2025-21758) protection using the Search tool and Edit the protection's settings.
Install policy on all Security Gateways.

This protection's log will contain the following information:

Attack Name: Application Servers Protection Violation.
Attack Information: Linux Kernel Denial of Service (CVE-2025-21758)