What is CVE-2026-63995?

CVE-2026-63995 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, affecting Linux kernel versions from 6.11 onward and 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.

What is the CVSS score for CVE-2026-63995?

CVE-2026-63995 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

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.

Is CVE-2026-63995 actively exploited?

CVE-2026-63995 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-63995

High

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.

Package Linux Kernel

Published 2026-07-19

Last modified 2026-07-30

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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.

Affected from

≥ 6.11

Fixed in

✓ 6.12.93 6.12.x ✓ 6.18.35 6.18.x ✓ 7.0.12 7.0.x ✓ 7.1

References

4 total

Details

CVE ID CVE-2026-63995

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2026-07-19

Modified 2026-07-30

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-63995?

CVE-2026-63995 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . 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.
What is the CVSS score for CVE-2026-63995?

CVE-2026-63995 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
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.
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.