CVE-2026-49422

Summary

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 Software

VendorProductVersion RangeStatus
FreeBSDFreeBSD15.1-RELEASE < p1affected
FreeBSDFreeBSD15.0-RELEASE < p11affected
FreeBSDFreeBSD14.4-RELEASE < p7affected
FreeBSDFreeBSD14.3-RELEASE < p16affected

Weaknesses

  • CWE-416: CWE-416: Use After Free

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

References