CVE-2026-63985 ethtool: eeprom: add more safeties to EEPROM Netlink fallback
A missing bounds check in the Linux kernel's ethtool EEPROM Netlink fallback allows attackers to read out-of-bounds memory, potentially disclosing sensitive kernel data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-63985?
CVE-2026-63985 is a high-severity vulnerability in Linux kernel, published on 19 Jul 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:
ethtool: eeprom: add more safeties to EEPROM Netlink fallback
The Netlink fallback path for reading module EEPROM (fallback_set_params()) validates that offset < eeprom_len, but does not check that offset + length stays within eeprom_len. The ioctl equivalent (ethtool_get_any_eeprom() in ioctl.c) has always enforced both bounds:
if (eeprom.offset + eeprom.len > total_len) return -EINVAL;
This could lead to surprises in both drivers and device FW. Add the missing offset + length validation to fallback_set_params(), mirroring the ioctl.
Similarly - ethtool core in general, and ethtool_get_any_eeprom() in particular tries to zero-init all buffers passed to the drivers to avoid any extra work of zeroing things out. eeprom_fallback() uses a plain kmalloc(), change it to zalloc.
Weakness: CWE-125
Which versions are affected by CVE-2026-63985?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-63985?
Apply the vendor's patch.
Is CVE-2026-63985 being exploited?
There is no known exploitation of CVE-2026-63985 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-63985, DEBIAN-CVE-2026-63985, GHSA-69m3-xqhx-p784, ROOT-OS-UBUNTU-2204-CVE-2026-63985, UBUNTU-CVE-2026-63985.