CVE-2026-49422
Use-after-free in TCP RACK stack option handler
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-416 |
| Vendor | freebsd |
| Product | freebsd |
| Published | Aug 19, 2026 |
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Affected Versions
FreeBSD / FreeBSD
15.1-RELEASE < p1 15.0-RELEASE < p11 14.4-RELEASE < p7 14.3-RELEASE < p16
References
Credits
Maik Muench