What’s Vulnerable › Vulnerabilities

CVE-2026-63991: Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt()

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-19 · updated 2026-10-07
• Weakness: CWE-476

Description

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 products

• Linux kernel: from 3.14 before 5.10.259; from 5.11 before 5.15.210; from 5.16 before 6.1.176; from 6.2 before 6.6.143; from 6.7 before 6.12.93; from 6.13 before 6.18.35 — fixed in 5.10.259, 5.15.210, 6.1.176, 6.12.93, 6.18.35, 6.6.143

How to fix

Upgrade to a fixed version: Linux kernel 5.10.259, 5.15.210, 6.1.176, 6.12.93. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/2061d080a013c0ec0a56162cd501fb36d2befc26
• https://git.kernel.org/stable/c/3c40d381ce04f9575a5d8b542898183c3b4b38dc
• https://git.kernel.org/stable/c/3d5d81d294ba09487c86bc4ba33dc4a4bec5d215
• https://git.kernel.org/stable/c/9903a04becf059e44cccf625e23689b7d4378384
• https://git.kernel.org/stable/c/9afcb5ea080af13aab37930da627db43bd277665
• https://git.kernel.org/stable/c/b06203ac5f12929d79146bb9f063c2af1d679e63
• https://git.kernel.org/stable/c/d630c4b25f36e0e68461561e4c70957ec37fdedd
• https://git.kernel.org/stable/c/e673889a35a5e4c586d0fae67d8755ca4367d3e2

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