CVE-2026-99122 vsock/vmci: validate packet source for connected sockets
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-99122?
CVE-2026-99122 is a vulnerability in Linux, published on 28 Oct 2026.
Official description
In the Linux kernel, the following vulnerability has been resolved:
vsock/vmci: validate packet source for connected sockets
vmci_transport_recv_stream_cb() looks up sockets first by the full source and destination tuple, then by destination only in the bound table. The fallback can select a non-listening socket without checking whether the packet came from its stored peer.
This was reproduced with two VMCI contexts. A RST from the context not stored in a TCP_SYN_SENT socket reset that socket after it was selected by the destination-only lookup.
VMCI can process notification packets in bottom-half context when the socket is not owned by user context, or defer packets to a workqueue. Use vsock_check_source() after taking the socket lock in the bottom-half path, and recheck after lock_sock() in the workqueue path. Listening sockets continue to accept packets from any source.
Reply with a RST addressed from the received packet before dropping a source that fails validation. This preserves the existing reset behavior for bound non-listening and concurrently closed sockets without directing the reset to a connected socket's stored peer.
Which versions are affected by CVE-2026-99122?
How do I fix CVE-2026-99122?
Upgrade to a fixed version.
Is CVE-2026-99122 being exploited?
There is no known exploitation of CVE-2026-99122 in the wild and no public exploit code.
Sources
Also known as AZL-111224, BELL-CVE-2026-99122, DEBIAN-CVE-2026-99122, GHSA-99x3-rpwc-xh78, UBUNTU-CVE-2026-99122.