CVE-2023-40548: Fedoraproject Fedora

High severity, CVSS 7.4. EPSS: 0.4% chance of exploitation in the next 30 days.

A buffer overflow was found in Shim in the 32-bit system. The overflow happens due to an addition operation involving a user-controlled value parsed from the PE binary being used by Shim. This value is further used for memory allocation operations, leading to a heap-based buffer overflow. This flaw causes memory corruption and can lead to a crash or data integrity issues during the boot phase.

Affected products

• Fedoraproject Fedora: version 39 only
• Red Hat Shim: before 15.8 (fixed in 15.8); version 15.8 only

Published 2024-01-29. Last modified 2026-06-26.