CVE-2025-70100: Gkostka LWEXT4

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

A divide-by-zero vulnerability in the ext4_block_set_lb_size function in src/ext4_blockdev.c of the lwext4 1.0.0 library allows attackers to cause a denial of service by providing a malformed ext4 filesystem image that results in a zero logical block size. The vulnerability is triggered during mount or image processing and leads to a Floating-Point Exception (FPE) under sanitizers or a runtime crash in standard builds due to missing validation of lb_size.

Affected products

Published 2026-06-03. Last modified 2026-07-22.