CVE-2026-53015: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: erofs: unify lcn as u64 for 32-bit platforms As sashiko reported [1], `lcn` was typed as `unsigned long` (or `unsigned int` sometimes), which is only 32 bits wide on 32-bit platforms, which causes `(lcn << lclusterbits)` to be truncated at 4 GiB. In order to consolidate the logic, just use `u64` consistently around the codebase. [1] https://sashiko.dev/r/20260420034612.1899973-1-hsiangkao%40linux.alibaba.com

Affected products

• Linux Linux Kernel: from 5.3, before 6.12.91 (fixed in 6.12.91); from 6.13, before 6.18.33 (fixed in 6.18.33); from 6.19, before 7.0.10 (fixed in 7.0.10)

Published 2026-06-24. Last modified 2026-07-15.