CVE-2026-45889 Details
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.
A vulnerability in the Linux kernel's Multipath TCP (MPTCP) implementation has been addressed. The issue arose from the MPTCP-level out-of-order (OoO) data being incorrectly accounted for in the MPTCP receive buffer growth function. This mismanagement could lead to the receive buffer drifting towards the maximum TCP receive memory limit, potentially causing performance issues. Additionally, the flaw introduced a rare race condition that could trigger a divide-by-zero error, crashing the kernel. The vulnerability affected the Linux kernel stable tree.
Users can upgrade to the latest version of the Linux kernel where this vulnerability has been fixed. Instructions for upgrading the kernel can be found in the official Linux kernel documentation.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/400ee4854adef1e4983812a3decf6717ea020136 | kernel.org | Patch |
| https://git.kernel.org/stable/c/6b329393502e5857662b851a13f947209c588587 | kernel.org | Patch |
| https://git.kernel.org/stable/c/fb7bf00b04a6b48859f52035d4e745848c2b4c79 | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-369 | Divide By Zero | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 6.18, < 6.18.14 >= 6.19, < 6.19.4 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 25, 2026 | Initial Analysis | [email protected] |
| Jun 17, 2026 | CVE Modified | kernel.org |
| May 27, 2026 | New CVE Received | kernel.org |