What is CVE-2026-63999?

CVE-2026-63999 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a Memory Leak flaw (CWE-401), affecting Linux kernel versions from 5.15.181 onward and patched in 6.18.35, 7.0.12 and 7.1. CVE-2026-63999 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-63999?

CVE-2026-63999 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-63999?

Yes, CVE-2026-63999 has been patched. Fixed versions include 6.18.35, 7.0.12 and 7.1. If you are running Linux kernel 5.15.181 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-63999 actively exploited?

CVE-2026-63999 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Memory Leak (CWE-401)?

The product does not release memory after use, causing gradual resource exhaustion. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/401.html

CVE-2026-63999

Medium

In the Linux kernel, the following vulnerability has been resolved: ethtool: rss: fix indir_table and hkey leak on get_rxfh failure rss_prepare_get() allocates the indirection table and hash key buffer via rss_get_data_alloc(), then calls ops->get_rxfh() to populate them. If get_rxfh() fails, the function returns an error without freeing the allocation.

Package Linux Kernel

Published 2026-07-19

Last modified 2026-10-08

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-401

CVE-2026-63999 is a Memory Leak vulnerability

What is Memory Leak?

The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.15.181, 6.1.135, 6.6.88, 6.12.24, 6.13.12, 6.14.3, 6.15 and later are affected. Fixed in 6.18.35, 7.0.12, 7.1 and their respective stable series.

Affected from

≥ 5.15.181 ≥ 6.1.135 ≥ 6.6.88 ≥ 6.12.24 ≥ 6.13.12 ≥ 6.14.3 ≥ 6.15

Fixed in

✓ 6.18.35 6.18.x ✓ 7.0.12 7.0.x ✓ 7.1

References

3 total

Kernel Git
https://git.kernel.org/stable/c/266297692f97008ca48bc311775c087c59bd7fe3

Patch
Kernel Git
https://git.kernel.org/stable/c/33d05c22d6f227c5ae171c46df2f6f8bf48047ea

Patch
Kernel Git
https://git.kernel.org/stable/c/80d95d92f828cfcace955d673637d944178b435f

Patch

Details

CVE ID CVE-2026-63999

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-07-19

Modified 2026-10-08

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-63999?

CVE-2026-63999 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 5.15.181 onward and has been patched in 6.18.35, 7.0.12 and 7.1. CVE-2026-63999 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-63999?

CVE-2026-63999 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-63999?

Yes. CVE-2026-63999 has been patched. Fixed versions include 6.18.35, 7.0.12 and 7.1. If you are running Linux kernel 5.15.181 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-63999 actively exploited?

No. CVE-2026-63999 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.