CVE-2026-23000
📋 TL;DR
A race condition vulnerability in the Linux kernel's mlx5e network driver causes a NULL pointer dereference when changing network profiles fails and leaves the network device in an invalid state. This leads to kernel crashes (denial of service) when subsequent attempts are made to modify the network configuration. Systems using Mellanox network adapters with the affected mlx5e driver are vulnerable.
💻 Affected Systems
- Linux kernel with mlx5e driver
📦 What is this software?
Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and complete denial of service, requiring physical or remote console access to reboot.
Likely Case
System crash when network configuration changes are attempted (e.g., enabling switchdev mode), causing temporary service disruption until reboot.
If Mitigated
No impact if the vulnerable code path is not triggered through network configuration changes.
🎯 Exploit Status
Requires privileged access to trigger network configuration changes. The vulnerability is triggered by legitimate operations failing in specific error conditions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel trees via provided git commits
Vendor Advisory: https://git.kernel.org/stable/c/4dadc4077e3f77d6d31e199a925fc7a705e7adeb
Restart Required: Yes
Instructions:
1. Update to a patched kernel version containing the fix. 2. Apply the specific patch from the stable kernel tree if backporting. 3. Reboot the system to load the new kernel.
🔧 Temporary Workarounds
Avoid network profile changes
linuxPrevent triggering the vulnerable code path by avoiding network configuration changes that modify mlx5e profiles
Disable switchdev mode
linuxEnsure switchdev mode is not enabled on affected Mellanox interfaces
# Check current mode: devlink dev eswitch show pci/0000:00:03.0
# Set to legacy mode: devlink dev eswitch set pci/0000:00:03.0 mode legacy
🧯 If You Can't Patch
- Monitor for kernel crash logs related to mlx5e_detach_netdev or NULL pointer dereferences at address 0x38
- Implement strict change control for network configuration operations on systems with Mellanox adapters
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if mlx5e driver is loaded: lsmod | grep mlx5; uname -rCheck Version:
uname -rVerify Fix Applied:
Verify the patch is applied by checking kernel version or examining the mlx5e driver code for the fix📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages mentioning mlx5e_detach_netdev
- NULL pointer dereference at address 0000000000000038
- System crash logs following network configuration changes
Network Indicators:
- Temporary network disruption on affected interfaces
SIEM Query:
kernel: *mlx5e* AND ("NULL pointer dereference" OR "Oops" OR "kernel panic")