Memory Corruption Vulnerability in Zephyr Ext2 Filesystem Driver

CVE-2026-13215

What is CVE-2026-13215?

The Zephyr ext2 filesystem driver is vulnerable due to insufficient validation of the s_log_block_size field in the on-disk superblock. This oversight allows an attacker to manipulate the block size, leading to out-of-bounds writes that can corrupt memory in kernel mode. The vulnerability arises from the ext2_verify_disk_superblock() function failing to check the bounds on s_log_block_size, resulting in potential memory corruption or even execution of arbitrary code. Attackers can exploit this by presenting a crafted ext2 filesystem image from any accessible storage medium. The issue is mitigated by rejecting s_log_block_size values that could lead to unsafe block sizes, thereby protecting against the described vulnerabilities.

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