CVE-2026-63991
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt() The skb_clone() function can return NULL if memory allocation fails. send_mcast_pkt() calls skb_clone() without checking the return value, which can lead to a NULL pointer dereference in send_pkt() when it dereferences skb->data. Add a NULL check after skb_clone() and skip the peer if the clone fails.
Affected versions
Linux kernel versions
3.14
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.
References
8 totalFrequently asked questions
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What is CVE-2026-63991?
CVE-2026-63991 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 3.14 onward and has been patched in 5.10.259, 5.15.210, 6.1.176 and others. CVE-2026-63991 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-2026-63991?
Yes — CVE-2026-63991 has been patched. Fixed versions include 5.10.259, 5.15.210, 6.1.176 and others. If you are running Linux kernel 3.14 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-63991 actively exploited?
No — CVE-2026-63991 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.