Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: allow subflow rcv wnd to shrink In MPTCP connection, the `window` field in the TCP header refers to the MPTCP-level rcv_nxt and it's right edge should not move backward. Such constraint is enforced at DSS option generation time. At the same time, the TCP stack ensures independently that the TCP-level rcv wnd right's edge does not move backward. That in turn causes artificial inflating of the MPTCP rcv window when the incoming data is acked at the TCP level and is OoO in the MPTCP sequence space (or lands in the backlog). As a consequence, the incoming traffic can exceed the receiver rcvbuf size even when the sender is not misbehaving. Prevent such scenario forcibly allowing the TCP subflow to shrink the TCP-level rcv wnd regardless of the current netns setting.
References
- https://git.kernel.org/stable/c/653245266913f03fcf21cbca68eed5c197a33e52
- https://git.kernel.org/stable/c/aa3861f40ac32706d9e97bfac76984613e278788
- https://git.kernel.org/stable/c/b1fd13074f22105deec45aa02283e322733e0c2d
- https://git.kernel.org/stable/c/bf364b0f10b27679140699821f88af7f01e2a6e3
- https://git.kernel.org/stable/c/c297a4e65c50a2b807d9309b22615080faffa8f3
- https://git.kernel.org/stable/c/da23be77e1292cd611e736c3aa17da633d7ddce7
FAQ
What is CVE-2026-53183?
CVE-2026-53183 is a documented vulnerability. In the Linux kernel, the following vulnerability has been resolved: mptcp: allow subflow rcv wnd to shrink In MPTCP connection, the `window` field in the TCP header refers to the MPTCP-level rcv_nxt...
How severe is CVE-2026-53183?
CVSS scoring is not yet available for CVE-2026-53183. Check NVD for updates.
Is there a patch for CVE-2026-53183?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.