Out-of-bounds read in Linux kernel - CVE-2026-64527
Published: July 27, 2026
Vulnerability identifier: #VU139405
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-64527
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in hyperv_receive() and hyperv_receive_sub() in the Hyper-V DRM protocol handler when handling oversized or malformed VMBus packets. A remote attacker can send a specially crafted VMBus packet to cause a denial of service.
An error path may report a required packet length larger than the 16 KiB receive buffer, leading the code to use that length unsafely if forwarded for copying.
How to mitigate CVE-2026-64527
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/049a6b474823049fe60212f25f26e4b30f44ee8f
- https://git.kernel.org/stable/c/164dc7bf17609340233c6bf4f66bb7c7008a0511
- https://git.kernel.org/stable/c/57d5d697642e05d5dd2d40660817765943dd709f
- https://git.kernel.org/stable/c/588c84b461393ff1998ac7b97b04f953f642e0df
- https://git.kernel.org/stable/c/7f87763f47a3c22fb50265a00619ef10f2394b18
- https://git.kernel.org/stable/c/c8974d96b6a5496f33dc69a3ce28a7bf5078def4
- https://git.kernel.org/stable/c/f5251226551bfec98c4705641b6f94ff1f238d91