CVE-2026-63995: high-severity vulnerability in Linux
ethtool: cmis: validate start_cmd_payload_size from module
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.8epss 0.1%
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.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected products
Linux · LinuxRelated CVEs — Linux
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