Improper Initialization in Linux kernel - CVE-2026-63954
Published: July 20, 2026
Vulnerability identifier: #VU138691
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-2026-63954
CWE-ID: CWE-665
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 improper initialization in hpfs_check_free_dnodes in fs/hpfs/alloc.c when handling a failure from hpfs_map_dnode_bitmap. A local user can trigger the error path to cause a denial of service.
How to mitigate CVE-2026-63954
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/010b08084000ef018f1a8de5197087f3b91d8cfe
- https://git.kernel.org/stable/c/0886c6f257fe3663f80218aa1919b0f3f21bf22c
- https://git.kernel.org/stable/c/1648a3c7f4e18f46a4881920133fc4f2494185a0
- https://git.kernel.org/stable/c/1d73a533760bc5abb83b3cc759133596f7bb708f
- https://git.kernel.org/stable/c/4f37bb30b57d6d403d02673074555bd3c3602bef
- https://git.kernel.org/stable/c/7c58c55a2a16f7274772507bd1637be609351b4f
- https://git.kernel.org/stable/c/974820a59efde7c1a7e1260bcfe9bb81f833cc9f
- https://git.kernel.org/stable/c/d98d8562b3284b5a5c8eb67e71b794508e46e288