What is CVE-2026-63992?

CVE-2026-63992 is a unscored severity Linux kernel vulnerability, affecting Linux kernel versions from 5.9 onward and patched in 5.10.259, 5.15.210, 6.1.176 and others. CVE-2026-63992 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-63992?

CVE-2026-63992 has a CVSS score of pending NVD analysis out of 10, rated awaiting scoring severity.

Is there a patch available for CVE-2026-63992?

Yes, CVE-2026-63992 has been patched. Fixed versions include 5.10.259, 5.15.210, 6.1.176 and others. If you are running Linux kernel 5.9 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-63992 actively exploited?

CVE-2026-63992 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-63992

In the Linux kernel, the following vulnerability has been resolved: tunnels: do not assume transport header in iptunnel_pmtud_check_icmp() In some cases, iptunnel_pmtud_check_icmp() can be called while skb transport header is not set. This triggers an out-of-bound access, because (typeof(skb->transport_header))~0U is 65535. Access the icmp header based on IPv4 network header, after making sure icmp->type is present in skb linear part. Note that iptunnel_pmtud_check_icmpv6()) is fine.

Package Linux Kernel

Published 2026-07-19

Last modified 2026-07-19

Patch available

Yes

Affected versions

Linux kernel versions 5.9 and later are affected. Fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12, 7.1 and their respective stable series.

Affected from

≥ 5.9

Fixed in

✓ 5.10.259 5.10.x ✓ 5.15.210 5.15.x ✓ 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

8 total

Showing 5 of 8 references View all on NVD

Frequently asked questions

What is CVE-2026-63992?

CVE-2026-63992 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.9 onward and has been patched in 5.10.259, 5.15.210, 6.1.176 and others. CVE-2026-63992 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
Is there a patch available for CVE-2026-63992?

Yes — CVE-2026-63992 has been patched. Fixed versions include 5.10.259, 5.15.210, 6.1.176 and others. If you are running Linux kernel 5.9 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-63992 actively exploited?

No — CVE-2026-63992 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.