Use-after-free in Linux kernel - CVE-2026-63826
Published: July 21, 2026
Vulnerability identifier: #VU138833
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63826
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use-after-free in store_modes() and related framebuffer mode handling in fbdev when processing crafted framebuffer mode changes through ioctl or sysfs interfaces. A local user can trigger stale mode pointer dereferences to cause a denial of service.
The issue involves stale pointers in fb_display[i].mode and fb_info->mode after the framebuffer modelist is replaced and the old list is freed.
Affected software
Linux kernel
How to mitigate CVE-2026-63826
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/0d35f9f194a858567a21017d69318a51e3a822b9
- https://git.kernel.org/stable/c/2c1c805c65fb7dc7524e20376d6987721e73a0b1
- https://git.kernel.org/stable/c/5267eab88fa4c684459504b8be577ad64953b9a6
- https://git.kernel.org/stable/c/70f1e000b88cfa8ca3fd7f4d082647fc089a7769
- https://git.kernel.org/stable/c/c6765f39ed27014ff877b00a2efa494233404e17