CVE-2026-63995

High

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.

SeverityHigh
CVSS7.8
Exploit probability—
ProductLinux Kernel
PublishedJul 19, 2026
First seenJul 19, 2026

How to fix

Update
  • linux linux_kernel6.12.93, 6.18.35, 7.0.12 or later

Affected products

ProductAffected versionsFixed in
linux linux_kernel6.11 ≤ v < 6.12.93, 6.13 ≤ v < 6.18.35, 6.19 ≤ v < 7.0.12, 7.16.12.93, 6.18.35, 7.0.12

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.

CVE-2026-63995 · Linux Kernel · Dark Radar