CVE-2026-80792: Linux

EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix use-after-free in ip6_finish_output2() ip6_finish_output2() caches a pointer to the IPv6 destination address (daddr) before invoking lwtunnel_xmit(). The LWT-BPF transmit path or other encapsulation operations within lwtunnel_xmit() can reallocate the skb head, freeing the memory that daddr points to. When lwtunnel_xmit() returns LWTUNNEL_XMIT_CONTINUE, the function continues to use the stale daddr pointer to compute the nexthop and to look up or create the neighbour entry. This results in a use-after-free read, which can leak sensitive kernel data, pollute the neighbour table with arbitrary values, misdirect traffic, or crash the system. Fix this by re-fetching the IPv6 header and the destination address pointer after lwtunnel_xmit() returns LWTUNNEL_XMIT_CONTINUE, ensuring that the subsequent nexthop computation and neighbour lookup operate on valid memory.

Affected products

• Linux Linux: from 5.10.233, before 5.10.267 (fixed in 5.10.267); from 5.4.289, before 5.5 (fixed in 5.5); from 5.15, before 5.15.218 (fixed in 5.15.218); from 5.16, before 6.1.185 (fixed in 6.1.185); from 6.2, before 6.6.154 (fixed in 6.6.154); from 6.7, before 6.12.106 (fixed in 6.12.106); …

Published 2026-09-04. Last modified 2026-09-04.