CVE-2026-31708

A flaw was found in the Linux kernel's Server Message Block (SMB) client. A malicious server can exploit an out-of-bounds read vulnerability by manipulating the OutputBufferLength during a QUERY_INFO operation. This can lead to the exposure of sensitive kernel memory to userspace, resulting in information disclosure.

SMB2 QUERY_INFO handling could read out of bounds on untrusted server responses. Red Hat treats this as SMB client parser hardening against malicious servers. Install corrected kernels; cifs unload reduces client exposure where acceptable.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent the cifs module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.