In the Linux kernel, the following vulnerability has been resolved:
xfrm: espintcp: fix UAF during close
ZDI reported and analyzed a race condition during close for espintcp sockets:
espintcp_close() frees emsg->skb via kfree_skb() without holding any socket lock. Concurrently, the xfrm_trans_reinject work queue invokes esp_output_tcp_finish() -> espintcp_push_skb() -> espintcp_push_msgs() -> skb_send_sock_locked(), which reads the same skb as a data source.
Fix this by adding a synchronize_rcu() call after resetting sk_prot, since esp_output_tcp_finish() runs under RCU and won't use a socket with sk_prot == &tcp_prot. Simply taking the socket lock in espintcp_close() could lead to leaks, if esp_output_tcp_finish() re-adds an skb in the slot we just freed. After this, the existing barrier() is no longer needed.
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade linux | Sep 21, 2026 | Sep 4, 2026 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Sep 21, 2026 | Sep 4, 2026 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub