CVE-2026-63995

Published: July 22, 2026Last modified: July 22, 2026

Description

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.

Severity score breakdown

Status

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