CVE-2026-63867
mptcp: close TOCTOU race while computing rcv_wnd
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
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.
| Vendor | linux |
| Product | linux |
| Ecosystems | |
| Industries | Technology |
| Published | Jul 19, 2026 |
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Affected Versions
Linux / Linux
fa3fe2b150316b294f2c662653501273ff25bba8 < 301a33fd590c408a05c5df800e0cc1e6a8a2f8f8 fa3fe2b150316b294f2c662653501273ff25bba8 < 68364963e5baf03f16b4420292291f75c8f66497 fa3fe2b150316b294f2c662653501273ff25bba8 < 907ac6b1658e0277f979fcdfae2a753b495c1510 fa3fe2b150316b294f2c662653501273ff25bba8 < c4f4cf60797974873dbc8e100144682a6f2f861f fa3fe2b150316b294f2c662653501273ff25bba8 < 3b8cbba7c0ed31189c89f90be247b8973ffa79ef fa3fe2b150316b294f2c662653501273ff25bba8 < 8f4f0a157e8436a05bf8c3670b24dbc258911c43 fa3fe2b150316b294f2c662653501273ff25bba8 < 8ab24fdebc369c0dfb90f82c1650b1e66662bb45
Linux / Linux
5.11
References
git.kernel.org: https://git.kernel.org/stable/c/301a33fd590c408a05c5df800e0cc1e6a8a2f8f8 git.kernel.org: https://git.kernel.org/stable/c/68364963e5baf03f16b4420292291f75c8f66497 git.kernel.org: https://git.kernel.org/stable/c/907ac6b1658e0277f979fcdfae2a753b495c1510 git.kernel.org: https://git.kernel.org/stable/c/c4f4cf60797974873dbc8e100144682a6f2f861f git.kernel.org: https://git.kernel.org/stable/c/3b8cbba7c0ed31189c89f90be247b8973ffa79ef git.kernel.org: https://git.kernel.org/stable/c/8f4f0a157e8436a05bf8c3670b24dbc258911c43 git.kernel.org: https://git.kernel.org/stable/c/8ab24fdebc369c0dfb90f82c1650b1e66662bb45