Check Point Advisories

Linux Kernel Use After Free (CVE-2025-21759)

Vulnerability
Protection

Check Point Reference:	CPAI-2025-13452
Date Published:	23 Mar 2026
Severity:	High
Last Updated:	Monday 23 March, 2026
Source:
Industry Reference:	CVE-2025-21759
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	Linux Kernel 2.6.26 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 use after free vulnerability in Linux Kernel allows local attackers to exploit RCU protection flaws in igmp6_send() to cause a denial-of-service condition or gain elevated privileges.

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 Use After Free (CVE-2025-21759) 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 Use After Free (CVE-2025-21759)