Out-of-bounds read in Linux kernel - CVE-2026-64324
Published: July 27, 2026
Vulnerability identifier: #VU139662
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-2026-64324
CWE-ID: CWE-125
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 read in udf_free_blocks() and block bitmap handling in fs/udf/balloc.c when processing crafted UDF filesystem block extents. A local user can supply a crafted filesystem and truncate a writable file on it to cause a denial of service.
On systems where active users can mount removable UDF media without administrative privileges, user interaction is not required beyond mounting the media and truncating a file.
Affected software
Linux kernel
How to mitigate CVE-2026-64324
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/12af328d2ee8d68e81ba612246d0b54b22d23e1f
- https://git.kernel.org/stable/c/335202ab25b01fdd45889ff25eab70864686dea3
- https://git.kernel.org/stable/c/5f0419457f89dce1a3f1c8e62a3adf2f39ab8168
- https://git.kernel.org/stable/c/9442d75429b0c556292a7454fe888d54259f5240
- https://git.kernel.org/stable/c/b54aee5652fcd7c23a0904a4623ec462c3edc70c
- https://git.kernel.org/stable/c/be87de7789a82a030a4896bc7683415ec9fa6f2b
- https://git.kernel.org/stable/c/fb49099206c5c57af28a157249fa7bcb5518f99e
- https://git.kernel.org/stable/c/fdd6229d2ae9914c1f25d1041db0f4f312a4fa76