CVE-2026-45842

A flaw was found in the Linux kernel's SLIP (Serial Line Internet Protocol) and PPP (Point-to-Point Protocol) components. An unprivileged local user can exploit this vulnerability by manipulating the PPPIOCSMAXCID ioctl to configure the SLIP Compressed Header (SLHC) state incorrectly. This misconfiguration leads to a null pointer dereference when processing specific network frames, causing a kernel crash and resulting in a Denial of Service (DoS) for the affected system.

This vulnerability is rated as having a Moderate impact because exploitation is restricted to local actors with the ability to create unprivileged user namespaces to obtain network administration privileges, and the failure mode only causes a system crash without compromising confidentiality or integrity. In standard Red Hat Enterprise Linux server environments, legacy Point-to-Point Protocol (PPP) interfaces and SLIP compression are rarely utilized by default. Although an unauthenticated remote attacker cannot trigger the flaw directly, a malicious local account can induce a kernel panic, limiting the overall blast radius strictly to service availability.

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.