CVE-2026-63995

Updated on 19 Jul 2026

Severity

Awaiting Analysis

Details

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Overview

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

ethtool: cmis: validate start_cmd_payload_size from module

The CMIS firmware update code reads start_cmd_payload_size from the module’s FW Management Features CDB reply and uses it directly as the byte count for memcpy. The destination buffer is 112 bytes (ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH - 8). So a malicious module (or corrupted response) can cause a OOB write later on in cmis_fw_update_start_download().

Let’s error out. If modules that expect longer LPL writes actually exist we should revisit.

struct cmis_cdb_start_fw_download_pl’s definition has to move, no change there.

Details

Affected product:
AlmaLinux 9.2 ESU , TuxCare 9.6 ESU
Affected packages:
kernel @ 5.14.0 (+1 more)

Fixes