SB2026110856 - 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-2026-99272)

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

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause out-of-bounds kernel memory reads, potentially resulting in a denial of service or disclosure of sensitive information.

The vulnerability exists due to an out-of-bounds read in the Linux kernel SMB client's SMB2_read() function when processing synchronous read responses with unvalidated data offsets and lengths. A remote attacker can operate a malicious SMB server and return a crafted READ response with DataOffset set to 0 and DataLength set to 1067 to make the client copy 1067 bytes from a 448-byte receive object, potentially crashing the client or exposing sensitive kernel memory.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/1ba1937de005e261a8858f45bfef5da7458df94c
• https://git.kernel.org/stable/c/2ec9cdf469dd32bcf33073aeb30c08e9356e0ca1