SB2026032598 - Type conversion in Linux kernel firmware efi driver

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Main Vulnerability Database SB2026032598

SB2026032598 - Type conversion in Linux kernel firmware efi driver

Published: March 25, 2026

Security Bulletin ID SB2026032598
Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Type conversion (CVE-ID: CVE-2026-23352)

The vulnerability allows a local attacker to cause a denial of service.

The vulnerability exists due to improper memory management in the EFI boot services memory release mechanism when processing memory map initialization during system boot. A local attacker can trigger the early release of boot services memory before deferred memory map initialization is complete, leading to unfreed memory pages and a memory leak.

The issue specifically occurs on systems with CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, where memblock_free_late() skips uninitialized pages, resulting in a significant memory leak—up to approximately 140MB on constrained systems like EC2 t3a.nano instances with only 512MB RAM.


Remediation

Install update from vendor's website.

References