Improper input validation in Linux kernel - CVE-2026-98600

Vulnerability identifier: #VU156904

CSH Severity: Low

CVSS v4: 5.3 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98600

CWE-ID: CWE-20

Exploitation vector: Adjecent network

Exploit availability: No public exploit available

The vulnerability allows a remote attacker on the local network to cause RFCOMM header bytes to be delivered as application payload or interpreted as multiplexer control commands.

The vulnerability exists due to insufficient frame length validation in the Linux kernel's rfcomm_recv_frame() function when processing RFCOMM frames with an extended two-byte length field. A remote attacker on the local network can send a four-byte frame with EA set to zero and a valid frame check sequence to trigger an unchecked skb_pull() failure, leaving header bytes to be processed as application data or, on DLCI 0, as a multiplexer control command.

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/6d91041bb38b97e2feb625123cc0529d7b83a0e1
• https://git.kernel.org/stable/c/71ccacde407b7d8f0ef48974a0d2524602fd5c44
• https://git.kernel.org/stable/c/76876fd26569302d26d91cbe8b75fa8e66cf8969
• https://git.kernel.org/stable/c/7a1781a2f3a9667b3065d402d1f11986a2363e08
• https://git.kernel.org/stable/c/9240fc1f2cde5331c61608da21b00394602ca762
• https://git.kernel.org/stable/c/97711b964877242933484989224a3c4c5d88a5ee
• https://git.kernel.org/stable/c/be00deee60044ffa820f9436415caeb665b2cda0
• https://git.kernel.org/stable/c/c25587fa26761e623198b4f47151fe79d09ccde6

• Improper input validation in Linux kernel bluetooth rfcomm
• SUSE update for the Linux Kernel