[ CVE-2026-99270 · Published 3 Nov 2026 ]

Vulnerability in Linux

CVSS 8.1 EPSS <1%No fix listed yet

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: tcp: Fix potential UAF in reqsk_timer_handler(). When TCP socket migration fails at inet_ehash_insert() in reqsk_timer_handler(), we jump to the no_ownership: label and free the new reqsk immediately with __reqsk_free(). Thus, we must stop the new reqsk's timer before jumping to the label, but the timer might be missed since the cited commit, resulting in UAF. As we are in the original reqsk's timer context, we can safely call timer_delete_sync() for the new reqsk. Let's pass false to __inet_csk_reqsk_queue_drop() to stop the new reqsk's timer.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.