CVE-2026-68143

A flaw was found in the Linux kernel's SLIP (Serial Line Internet Protocol) network component. A race condition exists during an MTU (Maximum Transmission Unit) change when the system reallocates receive buffers. This can allow a remote attacker to trigger an out-of-bounds write or write to a freed memory region, potentially leading to a denial of service or arbitrary code execution.

This vulnerability has been rated as having an Important severity because kernel memory corruption can allow local users with network administration capabilities to crash the system or execute code. The Serial Line Internet Protocol (SLIP) driver is a legacy networking component that is not loaded by default in Red Hat Enterprise Linux. Exposure is limited to environments where SLIP hardware or virtual serial lines are explicitly configured and in active use.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this vulnerability, prevent the slip kernel module from loading if the SLIP protocol is not required. Create a file /etc/modprobe.d/disable-slip.conf with the content blacklist slip. Then, regenerate the initramfs using dracut -f -v. A system reboot is required for the changes to be fully applied. This action may impact systems relying on the SLIP protocol for network communication.