CVE-2026-63867
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of service disruption.
- Exploit odds
- 0.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.3% in the next 30 days (EPSS).
- Severity: 8.2 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-367
- Record status
- Analyzed
Affected
- Linux Kernel < 5.15.210
- Linux Kernel < 6.1.176
- Linux Kernel < 6.6.143
- Linux Kernel < 6.12.94
- Linux Kernel < 6.18.36
- Linux Kernel < 7.0.13
- Linux Kernel 7.1
Attack profile CVSS 3.1 · 8.2
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-63867.md and follow it. Check whether this project is affected by CVE-2026-63867. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/301a33fd590c408a05c5df800e0cc1e6a8a2f8f8
- https://git.kernel.org/stable/c/3b8cbba7c0ed31189c89f90be247b8973ffa79ef
- https://git.kernel.org/stable/c/68364963e5baf03f16b4420292291f75c8f66497
- https://git.kernel.org/stable/c/8ab24fdebc369c0dfb90f82c1650b1e66662bb45
- https://git.kernel.org/stable/c/8f4f0a157e8436a05bf8c3670b24dbc258911c43
- https://git.kernel.org/stable/c/907ac6b1658e0277f979fcdfae2a753b495c1510
- https://git.kernel.org/stable/c/c4f4cf60797974873dbc8e100144682a6f2f861f
References
- https://git.kernel.org/stable/c/301a33fd590c408a05c5df800e0cc1e6a8a2f8f8
- https://git.kernel.org/stable/c/3b8cbba7c0ed31189c89f90be247b8973ffa79ef
- https://git.kernel.org/stable/c/68364963e5baf03f16b4420292291f75c8f66497
- https://git.kernel.org/stable/c/8ab24fdebc369c0dfb90f82c1650b1e66662bb45
- https://git.kernel.org/stable/c/8f4f0a157e8436a05bf8c3670b24dbc258911c43
- https://git.kernel.org/stable/c/907ac6b1658e0277f979fcdfae2a753b495c1510
- https://git.kernel.org/stable/c/c4f4cf60797974873dbc8e100144682a6f2f861f