Out-of-bounds read in Linux kernel - CVE-2026-64448
Published: July 27, 2026
Vulnerability identifier: #VU139495
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-2026-64448
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 smb2_check_message() and subsequent SMB client protocol decoders when processing crafted SMB2 responses with a data area. A remote attacker can send a specially crafted SMB server response to disclose sensitive information.
The issue is reachable during NEGOTIATE and SESSION_SETUP before the session is established, including through the SPNEGO/negTokenInit and NTLMSSP challenge decoders when mounting against a non-conforming server.
Affected software
Linux kernel
How to mitigate CVE-2026-64448
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/31c6312608c60b72a1feb99a5afb680645a3e8a3
- https://git.kernel.org/stable/c/419ec1b604d7fb60c10aec2dc062371f9fcd4940
- https://git.kernel.org/stable/c/53b7c271f06be4dd5cfc8c6ef552a8355c891a7f
- https://git.kernel.org/stable/c/573e502d14714d2947e22e7eff40ec20a6a44a42
- https://git.kernel.org/stable/c/6e9d10f62773b99bd927940fd9cbdfe7207e23ff
- https://git.kernel.org/stable/c/8d0bbc78046d264bbf6a574ea6f9072258a43e35
- https://git.kernel.org/stable/c/b6a381c01e2ac98a48e32ac0f2a45bbadd9e26b0
- https://git.kernel.org/stable/c/ceb875a375dedbf51c9425c1d13a2d7a8435c08c