CVE-2026-31675

Updated on 25 Apr 2026

Severity

7.8 High severity

Details

CVSS score
7.8

Overview

About vulnerability

In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_netem: fix out-of-bounds access in packet corruption In netem_enqueue(), the packet corruption logic uses get_random_u32_below(skb_headlen(skb)) to select an index for modifying skb->data. When an AF_PACKET TX_RING sends fully non-linear packets over an IPIP tunnel, skb_headlen(skb) evaluates to 0. Passing 0 to get_random_u32_below() takes the variable-ceil slow path which returns an unconstrained 32-bit random integer. Using this unconstrained value as an offset into skb->data results in an out-of-bounds memory access. Fix this by verifying skb_headlen(skb) is non-zero before attempting to corrupt the linear data area. Fully non-linear packets will silently bypass the corruption logic. A flaw was found in the Linux kernel’s netem (network emulator) module. When processing certain non-linear network packets, specifically those sent via an AF_PACKET TX_RING over an IPIP tunnel, a calculation error can occur. This error leads to an out-of-bounds memory access, which could result in system instability or a denial of service.

Details

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
Debian 13 Planned
Ubuntu 24.04 Planned