Time-of-check Time-of-use (TOCTOU) Race Condition in Linux kernel - CVE-2026-99239

Vulnerability identifier: #VU158719

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-99239

CWE-ID: CWE-367

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to potentially disclose sensitive information, modify system data, or cause a denial of service.

The vulnerability exists due to a time-of-check time-of-use race condition in the Linux kernel Bluetooth L2CAP channel management code when binding and connecting a socket concurrently. A local user can race bind and connect operations to link the same channel to a connection more than once, violating assumptions used during channel cleanup and potentially compromising system confidentiality, integrity, and availability.

Linux kernel
openEuler
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo

Install security update from vendor's repository.

kernel - update to 5.10.0-341.0.0.242
bpftool - update to 5.10.0-341.0.0.242
bpftool-debuginfo - update to 5.10.0-341.0.0.242
kernel-debuginfo - update to 5.10.0-341.0.0.242
kernel-debugsource - update to 5.10.0-341.0.0.242
kernel-devel - update to 5.10.0-341.0.0.242
kernel-headers - update to 5.10.0-341.0.0.242
kernel-source - update to 5.10.0-341.0.0.242
kernel-tools - update to 5.10.0-341.0.0.242
kernel-tools-debuginfo - update to 5.10.0-341.0.0.242
kernel-tools-devel - update to 5.10.0-341.0.0.242
perf - update to 5.10.0-341.0.0.242
perf-debuginfo - update to 5.10.0-341.0.0.242
python3-perf - update to 5.10.0-341.0.0.242
python3-perf-debuginfo - update to 5.10.0-341.0.0.242

• https://git.kernel.org/stable/c/10c705dd706aa93164ba41f2566f15206d6c178e
• https://git.kernel.org/stable/c/52fe88e4ef87311eee32b45c65603e7c69e75e7d
• https://git.kernel.org/stable/c/73820561d8cbfd3364a29b8fa77f1707f26029da
• https://git.kernel.org/stable/c/820579652b24ce277e0097cd65b42bd9b7b8bf07
• https://git.kernel.org/stable/c/85cc289eb08afa975375f838187369e68b429ee0
• https://git.kernel.org/stable/c/d3afd7803f9bc2a8c4270199497b60158b2fc647
• https://git.kernel.org/stable/c/e618d928ec7f88cbeadfa3542adcac40f474e629
• https://git.kernel.org/stable/c/fabaff1c59ff2cc89cb7e5bd0186a5e15f0c73b2

• Time-of-check Time-of-use (TOCTOU) Race Condition in Linux kernel bluetooth
• openEuler 22.03 LTS SP4 update for kernel