In the Linux kernel, the following vulnerability has been resolved: Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt() The… (CVE-2026-63991)
A vulnerability in the Linux kernel's Bluetooth 6lowpan implementation was resolved by adding a check for the return value of skb_clone() in the send_mcast_pkt() function. Without this check, a NULL pointer dereference could occur if skb_clone() fails and returns NULL, leading to a potential kernel crash. The fix involves skipping the peer if the clone fails to prevent dereferencing a NULL pointer.
AI Analysis
Technical Summary
The Linux kernel Bluetooth 6lowpan code had a flaw where send_mcast_pkt() called skb_clone() without verifying if the clone succeeded. Since skb_clone() can return NULL on memory allocation failure, dereferencing skb->data in send_pkt() could cause a NULL pointer dereference. The vulnerability was addressed by adding a NULL check after skb_clone() and skipping the peer if cloning fails, preventing the kernel from dereferencing a NULL pointer.
Potential Impact
This vulnerability can lead to a NULL pointer dereference in the Linux kernel, which may cause a kernel crash or denial of service. There is no indication of code execution or privilege escalation from the provided data. No known exploits in the wild have been reported.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to check the return value of skb_clone() in send_mcast_pkt() and skip the peer if cloning fails. Users should apply the official kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor or Linux kernel advisories for the current remediation guidance.
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt() The… (CVE-2026-63991)
Description
A vulnerability in the Linux kernel's Bluetooth 6lowpan implementation was resolved by adding a check for the return value of skb_clone() in the send_mcast_pkt() function. Without this check, a NULL pointer dereference could occur if skb_clone() fails and returns NULL, leading to a potential kernel crash. The fix involves skipping the peer if the clone fails to prevent dereferencing a NULL pointer.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel Bluetooth 6lowpan code had a flaw where send_mcast_pkt() called skb_clone() without verifying if the clone succeeded. Since skb_clone() can return NULL on memory allocation failure, dereferencing skb->data in send_pkt() could cause a NULL pointer dereference. The vulnerability was addressed by adding a NULL check after skb_clone() and skipping the peer if cloning fails, preventing the kernel from dereferencing a NULL pointer.
Potential Impact
This vulnerability can lead to a NULL pointer dereference in the Linux kernel, which may cause a kernel crash or denial of service. There is no indication of code execution or privilege escalation from the provided data. No known exploits in the wild have been reported.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to check the return value of skb_clone() in send_mcast_pkt() and skip the peer if cloning fails. Users should apply the official kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor or Linux kernel advisories for the current remediation guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-5hvm-w645-g9wh
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-63991"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a5d27aa2a4a8d598912e258
Added to database: 07/19/2026, 19:38:18 UTC
Last enriched: 07/19/2026, 20:03:08 UTC
Last updated: 07/20/2026, 18:58:20 UTC
Views: 12
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