An 8‑byte data structure in the Linux IPv4 stack was accessed on ARM64 devices using a 64‑bit load that required natural alignment. When the kernel was compiled with Clang and link‑time optimization, the loader performed an unaligned 64‑bit load, causing a strict Alignment Fault that immediately panicked the kernel. The flaw does not expose data or modify memory dishonestly; it simply brings the system down, resulting in a loss of availability. The weakness is identified as atomic read/write of a non‑aligned structure, corresponding to CWE‑468.

The issue affects Linux kernels for ARM64 that were compiled with Clang and have LTO enabled, before the patch that moves the READ_ONCE and WRITE_ONCE macros to operate on the 32‑bit members. Any system running an unpatched kernel on ARM64, regardless of the device type, is vulnerable if it uses the IPv4 multipath hash seed sysctl. This includes embedded platforms, servers, or mobile devices that build the kernel with Clang LTO.

The CVSS score of 5.5 indicates moderate severity, while the EPSS rate is below 1 %, suggesting a low likelihood of real‑world attacks. The vulnerability is not listed in the CISA KEV catalog, so no active exploitation is documented. For an attacker to trigger the fault, privileged operations that read or write the multipath hash seed sysctl would be required, implying a local or elevated privilege attack vector. When triggered, it results in an immediate denial of service via kernel panic.