CVE-2026-80848
N/AIn 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.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
—EPSS not yet scored
Impact if exploited
—CVSS · not scored
- No impact metrics
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-80848/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-80848/poc.json
References
Technical & other
- https://git.kernel.org/stable/c/29121c5e6591da527e8e36ddac7120dc527f574d
- https://git.kernel.org/stable/c/ed5d9102190c45fc70121c036b0626b740040b75
- https://git.kernel.org/stable/c/4bc0dfa28dca6fc0084203732695968049c44072
- https://git.kernel.org/stable/c/ff8dd7a932f34409a56e1b91a1219340f17457e9
- https://git.kernel.org/stable/c/4b31a875693c480c611519faca46216514e3e052
- https://git.kernel.org/stable/c/24efebecf415ba264adba0f0491cec436463a14f
- https://git.kernel.org/stable/c/eb3bbf29c723fe75c0eb92be14f0ec92971fe272
- https://git.kernel.org/stable/c/54b41ad14da9a981131ab6e4d3f79321a503ea5d
- https://git.kernel.org/stable/c/deb232e884877bf10b4ce2580909eedec986c284