Out-of-bounds read in Linux kernel - CVE-2026-63892
Published: July 20, 2026
Vulnerability identifier: #VU138759
CSH Severity: Low
CVSS v4.0: 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/E:U/U:Clear
CVE-ID: CVE-2026-63892
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to an out-of-bounds read and integer underflow in __tb_property_parse_dir() in the thunderbolt property parser when parsing a crafted non-root property directory with dir_len less than 4. A local user can provide crafted property data to trigger out-of-bounds memory access and cause a denial of service.
The issue affects the non-root parsing path, where a short directory length can cause a UUID copy to read past the end of the property block and can also cause entry walking to continue out of bounds until the kernel oopses.
How to mitigate CVE-2026-63892
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/37abc4504fa19d8f9f1e87792e8a2b8fdb308e40
- https://git.kernel.org/stable/c/3bec49ca55e08fb085cc4318f24b1b37eaab28cb
- https://git.kernel.org/stable/c/542a13890b742099c461d70920e97b14e568f6ec
- https://git.kernel.org/stable/c/5506c825f14d810f0690b1f4367cb7249ebb387a
- https://git.kernel.org/stable/c/d548179adcc87e1bc66b17e00352a1f536e76065
- https://git.kernel.org/stable/c/de21b59c29e31c5108ddc04210631bbfab81b997
- https://git.kernel.org/stable/c/de618299190b418291609e6921557253bd417e25
- https://git.kernel.org/stable/c/e2d4d51cf5785815fa4e91e0c019e3eb2506a84c