CVE-2025-39875 igb: Fix NULL pointer dereference in ethtool loopback test

What is CVE-2025-39875?

CVE-2025-39875 is a medium-severity vulnerability in Linux kernel, published on 23 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

igb: Fix NULL pointer dereference in ethtool loopback test

The igb driver currently causes a NULL pointer dereference when executing the ethtool loopback test. This occurs because there is no associated q_vector for the test ring when it is set up, as interrupts are typically not added to the test rings.

Since commit 5ef44b3cb43b removed the napi_id assignment in __xdp_rxq_info_reg(), there is no longer a need to pass a napi_id to it. Therefore, simply use 0 as the last parameter.

Weakness: CWE-476

Which versions are affected by CVE-2025-39875?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-39875?

Apply the vendor's patch.

Is CVE-2025-39875 being exploited?

There is no known exploitation of CVE-2025-39875 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2025-39875, DEBIAN-CVE-2025-39875, GHSA-h2wv-j9q6-hqmc, UBUNTU-CVE-2025-39875.