Critical Linux Kernel (Real-time) Security Update: USN-7608-3 Vulnerabilities Patched

 

Ubuntu has released USN-7608-3, patching critical Linux kernel (Real-time) vulnerabilities in GPU drivers, SMB, Netfilter & memory management. Learn how to update, mitigate risks, and secure systems with Ubuntu Pro for long-term protection.

Published: July 1, 2025

Overview: High-Risk Linux Kernel Vulnerabilities Addressed

The Linux kernel (Real-time) has been patched to resolve multiple critical security flaws that could allow attackers to compromise systems, escalate privileges, or execute arbitrary code.

 This update addresses vulnerabilities across key subsystems, including GPU drivers, SMB file sharing, memory management, Netfilter, and network traffic control.

🚨 Urgent Action Required: System administrators must apply these patches immediately to mitigate exploitation risks.

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Affected Packages & Update Instructions

Patched Linux Kernel (Real-time) Versions

Ubuntu Release	Package Version
22.04 (Jammy)	linux-image-5.15.0-1087-realtime – 5.15.0-1087.96
22.04 (Jammy)	linux-image-realtime – 5.15.0.1087.91

How to Apply the Update

1. Run a standard system update:

   bash

   sudo apt update && sudo apt upgrade  

2. Reboot your system to activate the new kernel.

3. Recompile third-party kernel modules (if applicable) due to an unavoidable ABI change.

⚠ Important Note: If you manually removed standard kernel metapackages (e.g., linux-generic), ensure proper reinstallation to avoid boot issues.

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Key Security Vulnerabilities Fixed (CVE List)

This update resolves critical flaws, including:

• CVE-2025-38001: GPU driver privilege escalation

• CVE-2025-38000: SMB file system remote code execution

• CVE-2025-37997: Memory management corruption

• CVE-2025-37932: Netfilter firewall bypass

• CVE-2025-37890: Network traffic control denial-of-service

🔍 Full CVE Details: Ubuntu Security Notices

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How to Reduce Future Security Risks

Upgrading to Ubuntu Pro extends security coverage to 25,000+ packages for 10 years, including Main and Universe repositories.

✅ Free for up to 5 machines – Get Ubuntu Pro Now

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FAQ: Linux Kernel Security Update

Q: Do I need to reboot after updating?

A: Yes, a reboot is mandatory to load the new kernel.

Q: What if I use custom kernel modules?

A: Recompile and reinstall them due to ABI changes.

Q: How do I check my current kernel version?

A: Run:

bash

uname -r