CVE-2026-63995
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 versions
Linux kernel versions
6.11
and later are affected. Fixed in
6.12.93,
6.18.35,
7.0.12,
7.1
and their respective stable series.
References
4 totalFrequently asked questions
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What is CVE-2026-63995?
CVE-2026-63995 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.11 onward and has been patched in 6.12.93, 6.18.35, 7.0.12 and others. CVE-2026-63995 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-63995?
Yes — CVE-2026-63995 has been patched. Fixed versions include 6.12.93, 6.18.35, 7.0.12 and others. If you are running Linux kernel 6.11 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-63995 actively exploited?
No — CVE-2026-63995 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.