CVE-2026-63867

CVE CVE-2026-63867EUVD EUVD-2026-45552Published 2026-07-19T14:18:37.000ZLast changed 2026-08-05T12:36:43.000ZCVSS 8.2

What the advisory describes

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.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Linux — Linux fa3fe2b150316b294f2c662653501273ff25bba8 <8f4f0a157e8436a05bf8c3670b24dbc258911c43; fa3fe2b150316b294f2c662653501273ff25bba8 <3b8cbba7c0ed31189c89f90be247b8973ffa79ef; patch: 5.15.210; patch: 6.18.36; patch: 7.1; fa3fe2b150316b294f2c662653501273ff25bba8 <907ac6b1658e0277f979fcdfae2a753b495c1510; patch: 6.6.143; patch: 7.0.13; patch: 6.1.176; fa3fe2b150316b294f2c662653501273ff25bba8 <301a33fd590c408a05c5df800e0cc1e6a8a2f8f8; patch: 6.12.94; patch: 0; fa3fe2b150316b294f2c662653501273ff25bba8 <68364963e5baf03f16b4420292291f75c8f66497; 5.11; fa3fe2b150316b294f2c662653501273ff25bba8 <c4f4cf60797974873dbc8e100144682a6f2f861f; fa3fe2b150316b294f2c662653501273ff25bba8 <8ab24fdebc369c0dfb90f82c1650b1e66662bb45

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

Linux — Linux

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