Out-of-bounds read in Linux kernel - CVE-2026-53402
Published: July 21, 2026
Vulnerability identifier: #VU138862
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-53402
CWE-ID: CWE-125
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 disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in fbcon_do_set_font() and subsequent rendering in the fbcon console subsystem when handling a failed font change rollback and later rendering user-controlled character indices. A local user can trigger a font change failure and then supply character indices greater than 255 to disclose sensitive information.
Exploitation requires a failure in the font-setting error path that leaves the console state desynchronized after vc_resize() fails.
How to mitigate CVE-2026-53402
Install security update from vendor's repository.