CVE-2026-80848
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.
Affected versions
Linux kernel versions
5.6
and later are affected. Fixed in
5.10.269,
5.15.220,
6.1.187,
6.6.156,
6.12.108,
6.18.49,
7.1.13,
7.2.3,
7.3
and their respective stable series.
References
9 totalFrequently asked questions
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What is CVE-2026-80848?
CVE-2026-80848 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.6 onward and has been patched in 5.10.269, 5.15.220, 6.1.187 and others. CVE-2026-80848 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-80848?
Yes. CVE-2026-80848 has been patched. Fixed versions include 5.10.269, 5.15.220, 6.1.187 and others. If you are running Linux kernel 5.6 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-80848 actively exploited?
No. CVE-2026-80848 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.