What is CVE-2026-63968?

CVE-2026-63968 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10, affecting Linux kernel versions from 6.1.128 onward and patched in 6.1.176, 6.6.143, 6.12.93 and others. CVE-2026-63968 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-63968?

CVE-2026-63968 has a CVSS score of 7.5 out of 10, rated High severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-63968?

Yes, CVE-2026-63968 has been patched. Fixed versions include 6.1.176, 6.6.143, 6.12.93 and others. If you are running Linux kernel 6.1.128 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-63968 actively exploited?

CVE-2026-63968 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-63968

High

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix possible infinite loop in fib6_select_path() Found while auditing the same pattern Sashiko reported in rt6_fill_node() [1]. Apply the same fix as commit f8d8ce1b515a ("ipv6: fix possible infinite loop in fib6_info_uses_dev()"). Writers holding tb6_lock can list_del_rcu(&first->fib6_siblings) without waiting for RCU readers; first->fib6_siblings.next then still points into the old ring and this softirq-side walker never reaches &first->fib6_siblings as its terminator. fib6_purge_rt() always WRITE_ONCE()s first->fib6_nsiblings to 0 before list_del_rcu(), so an inside-loop check is a reliable detach signal. [1] https://sashiko.dev/#/patchset/20260526020227.4857-1-jiayuan.chen%40linux.dev

Package Linux Kernel

Published 2026-07-19

Last modified 2026-07-30

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.5

out of 10

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 6.1.128, 6.6.75, 6.12.2, 6.11.11, 6.13 and later are affected. Fixed in 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12, 7.1 and their respective stable series.

Affected from

≥ 6.1.128 ≥ 6.6.75 ≥ 6.12.2 ≥ 6.11.11 ≥ 6.13

Fixed in

✓ 6.1.176 6.1.x ✓ 6.6.143 6.6.x ✓ 6.12.93 6.12.x ✓ 6.18.35 6.18.x ✓ 7.0.12 7.0.x ✓ 7.1

References

6 total

Showing 5 of 6 references View all on NVD

Details

CVE ID CVE-2026-63968

Severity High

CVSS score 7.5 / 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-2026-63968?

CVE-2026-63968 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 . It affects Linux kernel versions from 6.1.128 onward and has been patched in 6.1.176, 6.6.143, 6.12.93 and others. CVE-2026-63968 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-63968?

CVE-2026-63968 has a CVSS score of 7.5 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-63968?

Yes. CVE-2026-63968 has been patched. Fixed versions include 6.1.176, 6.6.143, 6.12.93 and others. If you are running Linux kernel 6.1.128 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-63968 actively exploited?

No. CVE-2026-63968 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.