Microsoft Security Response Center guidance
Vendor revision: Oct 2, 2026Release Notes
Vendor-listed releases
- 6.6.157.1-1
Vulnerability intelligence
CVE-2026-80792. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
Release Notes
Vendor-listed releases
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.
Source: NVD