Vulnerability · Published Jul 19, 2026 · Assigned by Linux

CVE-2026-63995ethtool: cmis: validate start_cmd_payload_size from module

High 7.8

In plain English

A high-severity out-of-bounds write in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.1%top 97.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:13linux6.12.94-1DEBIAN-CVE-2026-63995
Debian:14linux7.0.12-1DEBIAN-CVE-2026-63995
Ubuntu:26.04:LTSlinux7.0.0-28.28UBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-aws7.0.0-1009.9UBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-azure7.0.0-1010.10UBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-azure-7.07.0.0-1014.14~24.04.1UBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-azure-fde7.0.0-1009.9UBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-azure-fde-7.07.0.0-1013.13~24.04.1UBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-gcp7.0.0-1008.8UBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-gcp-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-gke7.0.0-1003.4UBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-28.28~24.04.1UBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-ibm7.0.0-1010.10UBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-nvidia7.0.0-1016.16UBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-nvidia-7.07.0.0-1016.16~24.04.1UBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-nvidia-bos7.0.0-2016.16UBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1009.9UBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-oracle7.0.0-1008.8UBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-oracle-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-raspi7.0.0-1015.15UBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-realtime7.0.0-28.28.1UBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-63995
Ubuntu:26.04:LTSlinux-riscv7.0.0-28.28.1UBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-63995
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-28.28.1~24.04.3UBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-63995
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-63995

Affected products (as reported)

VendorProductVersions
Linux Linux c4f78134d45c9619339c96b4bea380b1d0699788 – before 63112b4515469d00008452d9cfe3fb3bf1aa2df3c4f78134d45c9619339c96b4bea380b1d0699788 – before 0696709e951be54c699664adf546d16e28974d53c4f78134d45c9619339c96b4bea380b1d0699788 – before a46340da00385be7fb16c62425ebc20006f2d5d8c4f78134d45c9619339c96b4bea380b1d0699788 – before 12c2496a71f82f63617971ca9b730dffa05cf58b
Linux Linux 6.11

Weakness: CWE-787 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References