Use of Uninitialized Variable in Linux kernel - CVE-2026-98755

Vulnerability identifier: #VU157105

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98755

CWE-ID: CWE-457

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to obtain potentially sensitive kernel stack data.

The vulnerability exists due to use of an uninitialized stack variable in vcc_send_ctl() in drivers/tty/vcc.c when sending control packets through ldc_write(). A local user can receive control packets as the LDC peer to obtain kernel stack data potentially exposed through the uninitialized tag.stype_env field of the struct vio_vcc packet.

Linux kernel
SUSE Linux Micro
SUSE Linux Micro Extras
kernel-default
kernel-64kb
kernel-64kb-debugsource
kernel-64kb-devel
kernel-default-devel
kernel-syms
kernel-obs-build
kernel-obs-build-debugsource
kernel-default-debugsource
kernel-default-devel-debuginfo

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-default - update to 6.4.0-159998.55.1
kernel-64kb - update to 6.4.0-159998.55.1
kernel-64kb-debugsource - update to 6.4.0-159998.55.1
kernel-64kb-devel - update to 6.4.0-159998.55.1
kernel-default-devel - update to 6.4.0-159998.55.1
kernel-syms - update to 6.4.0-159998.55.1
kernel-obs-build - update to 6.4.0-159998.55.1
kernel-obs-build-debugsource - update to 6.4.0-159998.55.1
kernel-default-debugsource - update to 6.4.0-159998.55.1
kernel-default-devel-debuginfo - update to 6.4.0-159998.55.1

• https://git.kernel.org/stable/c/1f71f565e3585da1098ff19ca3c24687dab59185
• https://git.kernel.org/stable/c/399aa38af1d78001612e3130b2056ea392a355ca
• https://git.kernel.org/stable/c/4335278d0e75395cbfaf71c84b521df56d69e936
• https://git.kernel.org/stable/c/4b59afc8af3143ae03e4f9b81ca66aa5a1c1ebed
• https://git.kernel.org/stable/c/6f1a08ef02825b440126c406ea63ef6128888e15

• Use of Uninitialized Variable in Linux kernel tty driver
• SUSE update for the Linux Kernel