Out-of-bounds read in Linux kernel - CVE-2026-64578
Published: August 6, 2026
Vulnerability identifier: #VU141030
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64578
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in ksmbd_smb2_check_message() when processing a crafted compound SMB2 request. A remote attacker can send a specially crafted compound request with a trailing element that is too small to hold StructureSize2 to disclose sensitive information.
The issue occurs when the last compound element contains only a 64-byte SMB2 header, causing a 2-byte read at offset 64 to extend past the receive buffer.
Affected software
Linux kernel
How to mitigate CVE-2026-64578
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/15b38176fd1530372905c602fde51fe89ec8c877
- https://git.kernel.org/stable/c/2c307126ed8e7adddab82b8e31d962d3a2156ab1
- https://git.kernel.org/stable/c/ea128f06d2fb2186f0cac0c9f3e953e4d1f5c29a
- https://git.kernel.org/stable/c/f0e337e7db67cc1c832958bbb6c4026bdceacfdb
- https://git.kernel.org/stable/c/f7550a91ab211726f59cb137523b7a9eae1ac6eb