Junglewise Threat Intelligence

CVE-2026-63870: Linux Kernel uninitialized memory use in 6LoWPAN transmission

CVE-2026-63870 · Severity: info · CVSS 0 · Published 2026-07-19

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's networking component could allow an attacker to trigger a system crash or potentially access sensitive information. The issue occurs when the system attempts to process certain types of non-standard network traffic on low-power wireless interfaces (6LoWPAN). This could lead to operational disruptions or unauthorized data exposure on affected devices.

Technical details

A vulnerability exists in the Linux kernel's ieee802154 6LoWPAN implementation within the lowpan_xmit() and bt_xmit() functions. When a non-IPv6 packet (such as an ATA over Ethernet packet) is queued for transmission on a 6LoWPAN interface, the header creation function returns early without initializing the lowpan_addr_info structure. Subsequent calls to lowpan_header or setup_header unconditionally copy and use this uninitialized data from the skb headroom. This is a classic use of uninitialized memory vulnerability that can be triggered locally by a user or test case configuring a 6LoWPAN interface. The fix involves explicitly dropping non-IPv6 packets in the transmission path.

Affected products

  • Linux Linux Kernel 4.0 to 6.13

Timeline

  • 2026-06-03: patched: Initial patch authored by Eric Dumazet
  • 2026-07-19: disclosed: CVE published to NVD

References

Related threats