CVE-2026-53047

A flaw was found in the Linux kernel's EFI (Extensible Firmware Interface) capsule loader. An incorrect size calculation during memory reallocation for physical addresses can lead to an undersized buffer. This issue, specifically on 32-bit systems with Physical Address Extension (PAE), may result in a heap buffer overflow when storing physical addresses. This could potentially allow a local attacker to cause a denial of service or achieve arbitrary code execution.

This vulnerability is rated as Moderate because successful exploitation requires local administrative access to the EFI capsule interface and predominantly affects architectures where pointer sizes differ from physical address widths. Red Hat Enterprise Linux deployments operate on 64-bit platforms, where memory pointer and physical address representations share identical sizing, avoiding the buffer miscalculation that triggers out-of-bounds writes on 32-bit PAE configurations. Consequently, the practical risk to supported Red Hat environments is minimal, limited to local denial-of-service concerns under non-standard configurations.

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.