VULNERABILITY INTELLIGENCE

CVE-2026-49422

CVSS score8.4 HIGH
EPSS probability0.17%
CISA KEVNot currently listed
Published2026-08-19
Last modified2026-09-01
CVSS vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

Weakness classification

  • secteam@freebsd.org: CWE-416

Primary references