Improper access control in Linux kernel - CVE-2026-53188
Published: June 26, 2026
Vulnerability identifier: #VU135593
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-53188
CWE-ID: CWE-284
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to bypass device type validation.
The vulnerability exists due to improper access control in ib_get_ucaps() when handling a file descriptor for a device with a matching dev_t value. A local user can supply a file descriptor for a block device that masquerades as a ucap cdev to bypass device type validation.
The issue arises because relying only on dev_t is unsafe due to char/block aliasing.
How to mitigate CVE-2026-53188
Install security update from vendor's repository.