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CVE PROGRAM SOURCE RECORD8.4 High

CVE-2026-49422

Use-after-free in TCP RACK stack option handler

Description

The RACK setsockopt(2) handler drops the connection lock in order to copy option data from userspace, then reacquires the lock. After reacquiring, it verifies that the TCP stack had not been switched away, but did not reload its pointer to the stack's per-connection control block. If userspace switches stacks twice during this window, the check will succeed but the saved pointer will refer to freed memory. The bug may be exploitable by an unprivileged local user to escalate privileges.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

FreeBSD FreeBSD

Default version status: unknown

  • 15.1-RELEASE to < p1affected
  • 15.0-RELEASE to < p11affected
  • 14.4-RELEASE to < p7affected
  • 14.3-RELEASE to < p16affected

References