CVE-2026-74696: Linux

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: tcp: fix TFO max_qlen accounting across reuseport migration A listener's TCP_FASTOPEN max_qlen stops being accurate and lets through far more pending Fast Open requests than it was configured for. This only shows up with SO_REUSEPORT listener migration, where closing a listener hands its still-pending TFO children over to a surviving one. fastopenq.qlen is charged in tcp_fastopen_create_child() when the child is created and uncharged in reqsk_fastopen_remove() when the handshake completes. The uncharge follows rsk_listener of the request the child points at, and inet_reqsk_clone() has repointed the child at a new request owned by the new listener, so the ++ and the -- land on two different sockets. The new listener's qlen drifts negative and its limit no longer binds. Charge the new listener during migration, like reqsk_queue_migrated() already does for queue->young and queue->qlen.

Affected products

• Linux Linux: from 5.14, before 5.15.216 (fixed in 5.15.216); from 5.16, before 6.1.183 (fixed in 6.1.183); from 6.2, before 6.6.152 (fixed in 6.6.152); from 6.7, before 6.12.104 (fixed in 6.12.104); from 6.13, before 6.18.45 (fixed in 6.18.45); from 6.19, before 7.1.9 (fixed in 7.1.9)

Published 2026-08-22. Last modified 2026-08-25.