Reference page — cumulative record through Thursday, October 8, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-63991
Linux Linux — Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt()
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U N N H 5.5 .0022 11.4 —
AFFECTED
Product Versions Fixed
Linux 18722c247023035b9e2e2a08a887adec2a9a6e49 – —
Linux 3.14 – 5.10.259
TIMELINE
Jul 19 Reserved by Linux
Jul 19 Published (CNA: Linux)
Oct 7 ENRICHED — CVE-2026-63991 (Linux). Received CVSS 5.5 and CPE data from NVD.
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.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| July 19, 2026 | Reserved | Reserved by Linux |
| July 19, 2026 | Published | Published (CNA: Linux) |
| October 7, 2026 | ENRICHED | ENRICHED — CVE-2026-63991 (Linux). Received CVSS 5.5 and CPE data from NVD. |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| Linux | Linux | — | 18722c247023035b9e2e2a08a887adec2a9a6e49 | — |
| Linux | Linux | — | 3.14 | 5.10.259 |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-63991 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Thursday, October 8, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
