CVE-2026-63867
HIGH severity · CVSS 8.2 · CWE-367
8.2CVSS HIGH
Summary
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.
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactNone
Integrity impactLow
Availability impactHigh
Exploit probability (EPSS)0%
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
Affected products we track (1)
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.
Official patch: https://git.kernel.org/stable/c/301a33fd590c408a05c5df800e0cc1e6a8a2f8f8 ↗
Additional information
- NVD record
- https://git.kernel.org/stable/c/301a33fd590c408a05c5df800e0cc1e6a8a2f8f8Patch
- https://git.kernel.org/stable/c/3b8cbba7c0ed31189c89f90be247b8973ffa79efPatch
- https://git.kernel.org/stable/c/68364963e5baf03f16b4420292291f75c8f66497Patch
- https://git.kernel.org/stable/c/8ab24fdebc369c0dfb90f82c1650b1e66662bb45Patch
- https://git.kernel.org/stable/c/8f4f0a157e8436a05bf8c3670b24dbc258911c43Patch
- https://git.kernel.org/stable/c/907ac6b1658e0277f979fcdfae2a753b495c1510Patch
- https://git.kernel.org/stable/c/c4f4cf60797974873dbc8e100144682a6f2f861fPatch