CVE-2026-97563

A flaw was found in the Linux kernel's Server Message Block (SMB) client. When processing SMB version 1 responses, the read handler does not properly validate the data offset value sent by the server. A malicious or compromised SMB server can exploit this flaw by returning a crafted response with an out-of-bounds offset, triggering an out-of-bounds memory read beyond the response buffer. This flaw can lead to information disclosure by leaking adjacent kernel memory to user space, or cause a Denial of Service (DoS) through a system crash.

The paranoid score uses C:H because the patch establishes a real kernel heap read primitive and repeated attacker controlled offsets may disclose substantial adjacent memory. I:N is retained because neither the diff nor the described data flow provides an out of bounds write or another integrity primitive. AV:A reflects the usual internal SMB deployment. AV:N should be considered by an analyst if the vulnerable SMB1 client can connect to an attacker controlled server across routed or public networks. The supplied commit identifier is abbreviated and no verified CVE or full patch URL was provided.

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.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.