SB20260928381 - Out-of-bounds read in Linux kernel smb client

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds read (CVE-ID: CVE-2026-97563)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: 8.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to disclose kernel heap information or cause a denial of service.

The vulnerability exists due to insufficient validation of DataOffset in the CIFSSMBRead() SMB1 synchronous read helper when processing a crafted SMB1 read response. A remote attacker can return a response with a large DataOffset to read beyond the received response buffer and disclose adjacent kernel heap memory or trigger an oops.

Exploitation requires an explicitly configured SMB1 mount using vers=1.0, because SMB1 is not negotiated by default.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/5be5bdda5863eacc964b609ba927764f253431b3
• https://git.kernel.org/stable/c/667feba13e78d16393aacb15869f70970f422227