Out-of-bounds write in Linux kernel - CVE-2026-63869

Vulnerability identifier: #VU138791

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-2026-63869

CWE-ID: CWE-787

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to an out-of-bounds shift in ieee80211_parse_tx_radiotap() when parsing the radiotap header of an injected frame. A local user can supply a crafted frame from userspace to cause a denial of service.

The issue is triggered by the IEEE80211_RADIOTAP_ANTENNA value being used directly as a shift count, and larger antenna indices cannot be represented by the 2-bit bitmap.

Linux kernel
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Ubuntu
kernel-zfcpdump-devel (Red Hat package)
kernel-64k-devel (Red Hat package)
kernel-64k-debug-devel-matched (Red Hat package)
kernel-64k-debug-devel (Red Hat package)
rtla (Red Hat package)
kernel-zfcpdump-modules-extra (Red Hat package)
kernel-zfcpdump-modules-core (Red Hat package)
kernel-zfcpdump-modules (Red Hat package)
kernel-zfcpdump-devel-matched (Red Hat package)
kernel-64k-devel-matched (Red Hat package)
kernel-zfcpdump-core (Red Hat package)
kernel-zfcpdump (Red Hat package)
python3-perf (Red Hat package)
perf (Red Hat package)
kernel-uki-virt-addons (Red Hat package)
kernel-uki-virt (Red Hat package)
kernel-tools-libs (Red Hat package)
kernel-tools (Red Hat package)
kernel-rt-64k-debug-modules-extra (Red Hat package)
libperf (Red Hat package)
kernel-tools-libs-devel (Red Hat package)
kernel-cross-headers (Red Hat package)
rv (Red Hat package)
kernel-rt-64k-modules-extra (Red Hat package)
kernel-rt-64k-modules-core (Red Hat package)
kernel-rt-64k-modules (Red Hat package)
kernel-rt-64k-devel (Red Hat package)
kernel-rt-modules-extra (Red Hat package)
kernel-rt-64k-debug-modules-core (Red Hat package)
kernel-rt-64k-debug-modules (Red Hat package)
kernel-rt-64k-debug-devel (Red Hat package)
kernel-rt-64k-debug-core (Red Hat package)
kernel-rt-64k-debug (Red Hat package)
kernel-rt-64k-core (Red Hat package)
kernel-rt-64k (Red Hat package)
kernel-rt-modules-core (Red Hat package)
kernel-debug (Red Hat package)
kernel-debug-core (Red Hat package)
kernel-debug-devel (Red Hat package)
kernel-debug-devel-matched (Red Hat package)
kernel-debug-modules (Red Hat package)
kernel-debug-modules-core (Red Hat package)
kernel-debug-modules-extra (Red Hat package)
kernel-debug-uki-virt (Red Hat package)
kernel-devel (Red Hat package)
kernel-devel-matched (Red Hat package)
kernel-headers (Red Hat package)
kernel-modules (Red Hat package)
kernel-modules-core (Red Hat package)
kernel-modules-extra-matched (Red Hat package)
kernel-rt-modules (Red Hat package)
kernel-rt-devel (Red Hat package)
kernel-rt-debug-modules-extra (Red Hat package)
kernel-rt-debug-modules-core (Red Hat package)
kernel-rt-debug-modules (Red Hat package)
kernel-rt-debug-devel (Red Hat package)
kernel-rt-debug-core (Red Hat package)
kernel-rt-debug (Red Hat package)
kernel-rt-core (Red Hat package)
kernel-rt (Red Hat package)
kernel-modules-extra (Red Hat package)
linux (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-zfcpdump-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-64k-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-64k-debug-devel-matched (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-64k-debug-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
rtla (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump-devel-matched (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-64k-devel-matched (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-zfcpdump (Red Hat package) - update to 6.12.0-211.56.1.el10_2
python3-perf (Red Hat package) - update to 6.12.0-211.56.1.el10_2
perf (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-uki-virt-addons (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-uki-virt (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-tools-libs (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-tools (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-debug-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
libperf (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-tools-libs-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-cross-headers (Red Hat package) - update to 6.12.0-211.56.1.el10_2
rv (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-debug-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-debug-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-debug-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-debug-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-debug (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-64k (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-devel-matched (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-debug-uki-virt (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-devel-matched (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-headers (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-modules-extra-matched (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-debug-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-debug-modules-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-debug-modules (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-debug-devel (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-debug-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-debug (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt-core (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-rt (Red Hat package) - update to 6.12.0-211.56.1.el10_2
kernel-modules-extra (Red Hat package) - update to 6.12.0-211.56.1.el10_2
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13

• https://git.kernel.org/stable/c/033ce021a220913ac02416fcb5ac883a9ff8b6c7
• https://git.kernel.org/stable/c/6c0cf89f36ac0c0fd8687a4ccdce2efb23a9c663
• https://git.kernel.org/stable/c/9b40c59bab08f2a99abf969cc0bb92fa49de004b
• https://git.kernel.org/stable/c/f6d3dc8e8492bf8435e0b23c99472af7bafd6b44

• Out-of-bounds write in Linux kernel mac80211
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-gcp-7.0
• Red Hat Enterprise Linux 10 update for kernel