https://vulnerability.circl.lu/rss/recent/all/10 Most recent entries from all 2026-09-30T16:38:41.140170+00:00 Vulnerability-Lookup info@circl.lu python-feedgen Contains only the most 10 recent entries. https://vulnerability.circl.lu/vuln/cve-2026-63867 CVE-2026-63867 — mptcp: close TOCTOU race while computing rcv_wnd 2026-09-30T16:38:41.242840+00:00

Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

mptcp: close TOCTOU race while computing rcv_wnd

The MPTCP output path access locklessly the MPTCP-level ack_seq in multiple times, using possibly different values for the data_ack in the DSS option and to compute the announced rcv wnd for the same packet.

Refactor the cote to avoid inconsistencies which may confuse the peer. Also ensure that the MPTCP level rcv wnd is updated only when the egress packet actually contains a DSS ack.