CVE-2023-34256: Debian Linux

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

An issue was discovered in the Linux kernel before 6.3.3. There is an out-of-bounds read in crc16 in lib/crc16.c when called from fs/ext4/super.c because ext4_group_desc_csum does not properly check an offset. NOTE: this is disputed by third parties because the kernel is not intended to defend against attackers with the stated "When modifying the block device while it is mounted by the filesystem" access.

Affected products

• Debian Debian Linux: version 10.0 only
• Linux Linux Kernel: before 6.3.3 (fixed in 6.3.3)
• Suse Linux Enterprise: version 12.0 only; version 15.0 only

Published 2023-05-31. Last modified 2026-06-17.