Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: do not account for OoO in mptcp_rcvbuf_grow() MPTCP-level OoOs are physiological when multiple subflows are active concurrently and will not cause retransmissions nor are caused by drops. Accounting for them in mptcp_rcvbuf_grow() causes the rcvbuf slowly drifting towards tcp_rmem[2]. Remove such accounting. Note that subflows will still account for TCP-level OoO when the MPTCP-level rcvbuf is propagated. This also closes a subtle and very unlikely race condition with rcvspace init; active sockets with user-space holding the msk-level socket lock, could complete such initialization in the receive callback, after that the first OoO data reaches the rcvbuf and potentially triggering a divide by zero Oops.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 6.18, < 6.18.14 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/400ee4854adef1e4983812a3decf6717ea020136Patch
- https://git.kernel.org/stable/c/6b329393502e5857662b851a13f947209c588587Patch
- https://git.kernel.org/stable/c/fb7bf00b04a6b48859f52035d4e745848c2b4c79Patch
FAQ
What is CVE-2026-45889?
CVE-2026-45889 is a vulnerability with a CVSS score of 5.5 (MEDIUM). In the Linux kernel, the following vulnerability has been resolved: mptcp: do not account for OoO in mptcp_rcvbuf_grow() MPTCP-level OoOs are physiological when multiple subflows are active concurre...
How severe is CVE-2026-45889?
CVE-2026-45889 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-45889?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.