Out-of-bounds read in Linux kernel - CVE-2026-53040
Published: June 25, 2026
Vulnerability identifier: #VU135317
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-2026-53040
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 in the ocfs2 freefrag scan logic in fs/ocfs2/ioctl.c when processing a crafted filesystem through OCFS2_IOC_INFO with OCFS2_INFO_FL_NON_COHERENT. A local user can supply a crafted filesystem and issue the ioctl request to cause a denial of service.
The issue occurs in the non-coherent scan path, which reads raw group descriptor blocks without the validation performed by the coherent path.
How to mitigate CVE-2026-53040
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/05d0cbea41167b6b061c6ba5b70ee5a9a7a24c9e
- https://git.kernel.org/stable/c/0998674eec138c55e9e349b9cbd9dbc5129a9cc8
- https://git.kernel.org/stable/c/3e167e230d19cd273108bab2e4c61800fc335ae8
- https://git.kernel.org/stable/c/4c2d62ddde8928db12f4608950b67a20e67deab2
- https://git.kernel.org/stable/c/8f687eeed3da3012152b0f9473f578869de0cd7b
- https://git.kernel.org/stable/c/bb2906a1065ec28de021bac2ed03f2624edd7d07
- https://git.kernel.org/stable/c/bb3c54d1e71578521111f1a1ee7d5f4761a242b8
- https://git.kernel.org/stable/c/e0dcf12665d6dde37facf790803cdad44d5c328c