SB20260720230 - Out-of-bounds write in Linux kernel ethtool

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds write (CVE-ID: CVE-2026-63995)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 5.1 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows an attacker with physical access to cause memory corruption.

The vulnerability exists due to an out-of-bounds write in cmis_fw_update_start_download() when processing a CMIS module firmware management features reply. An attacker with physical access can provide a malicious module response with an oversized start command payload value to cause memory corruption.

A malicious module or a corrupted response can trigger the issue during CMIS firmware update handling.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0696709e951be54c699664adf546d16e28974d53
• https://git.kernel.org/stable/c/12c2496a71f82f63617971ca9b730dffa05cf58b
• https://git.kernel.org/stable/c/63112b4515469d00008452d9cfe3fb3bf1aa2df3
• https://git.kernel.org/stable/c/a46340da00385be7fb16c62425ebc20006f2d5d8