Out-of-bounds write in Linux kernel - CVE-2026-63869
Published: July 20, 2026
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
Vulnerability details
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.
Affected software
Linux kernel
How to mitigate CVE-2026-63869
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3