CVE-2026-74596

A flaw was found in the Linux kernel's fsverity subsystem. The vulnerability is due to the removal of a check in the setattr_prepare() function, which previously verified if fs-verity was enabled. This change allows fsverity files to be truncated even when the fs-verity feature is not active on the filesystem. This could lead to unintended modifications of fsverity protected files, potentially impacting data integrity.

A protection bypass in fsverity related setattr_prepare logic can allow size changes on files that are marked as verity protected when the kernel is built without CONFIG_FS_VERITY. This breaks the expected immutability property of fsverity files and may allow a local actor with sufficient file operation rights to truncate protected content that should not be modifiable. For the CVSS the PR:L is used because reliable triggering requires a local user or process context with permission to perform the truncate or size change operation on the affected file. The issue is not directly network reachable and does not indicate kernel memory corruption. Impact is primarily integrity loss for protected file contents, with a higher paranoid interpretation when fsverity is part of a local trust or package integrity model.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.