CVE-2026-80993 net: phylink: correctly validate returned PCS in phylink_inband_caps
A missing error check in the Linux kernel's phylink subsystem allows a local attacker to trigger a kernel panic via a null pointer dereference.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80993?
CVE-2026-80993 is a vulnerability in Linux, published on 11 Sep 2026. 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:
net: phylink: correctly validate returned PCS in phylink_inband_caps
In phylink_inband_caps(), the PCS returned by mac_select_pcs is only checked if NULL but mac_select_pcs can also return an error pointer.
This can cause a kernel panic as phylink_pcs_inband_caps() only checks if passed PCS is not NULL and directly dereference ops from the phylink_pcs struct.
Use the IS_ERR_OR_NULL macro to address both case where the returned PCS can be NULL or an error pointer and prevent a kernel panic.
Which versions are affected by CVE-2026-80993?
How do I fix CVE-2026-80993?
Apply the vendor's patch.
Is CVE-2026-80993 being exploited?
There is no known exploitation of CVE-2026-80993 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80993, DEBIAN-CVE-2026-80993, GHSA-v77c-jw3g-56gh, UBUNTU-CVE-2026-80993.