CVE-2026-46137

Analyzed Analyzed - Analysis Complete

Race Condition in Linux Kernel MPTCP PM ADD_ADDR Timer

Publication date: 2026-05-28

Last updated on: 2026-06-24

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: ADD_ADDR rtx: fix potential data-race This mptcp_pm_add_timer() helper is executed as a timer callback in softirq context. To avoid any data races, the socket lock needs to be held with bh_lock_sock(). If the socket is in use, retry again soon after, similar to what is done with the keepalive timer.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-05-28

Last Modified

2026-06-24

Generated

2026-07-08

AI Q&A

2026-05-29

EPSS Evaluated

2026-07-06

NVD

CVE-2026-46137

EUVD

EUVD-2026-32764

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	7.1
linux	linux_kernel	7.1
linux	linux_kernel	From 6.13 (inc) to 6.18.30 (exc)
linux	linux_kernel	From 6.2 (inc) to 6.6.141 (exc)
linux	linux_kernel	From 6.7 (inc) to 6.12.91 (exc)
linux	linux_kernel	From 6.19 (inc) to 7.0.7 (exc)
linux	linux_kernel	From 5.16 (inc) to 6.1.176 (exc)
linux	linux_kernel	From 5.11 (inc) to 5.15.210 (exc)
linux	linux_kernel	From 5.10 (inc) to 5.10.259 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-362	The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Attack-Flow Graph

Mitigation Strategies

The vulnerability has been resolved by ensuring that the socket lock is held with bh_lock_sock() during the mptcp_pm_add_timer() helper execution to avoid data races.

To mitigate this vulnerability, you should update your Linux kernel to a version that includes this fix.

Executive Summary

This vulnerability exists in the Linux kernel's multipath TCP (mptcp) implementation, specifically in the pm (path manager) component's ADD_ADDR retransmission logic. The issue arises because the mptcp_pm_add_timer() function, which is executed as a timer callback in a softirq context, does not properly hold the socket lock using bh_lock_sock(). This can lead to potential data races when accessing the socket.

To fix this, the socket lock must be held during the timer callback to prevent concurrent access issues. If the socket is currently in use, the timer should retry soon after, similar to the behavior of the keepalive timer.

Impact Analysis

The vulnerability could lead to data races in the Linux kernel's multipath TCP implementation, which may cause unpredictable behavior such as data corruption, crashes, or other stability issues in systems using this feature.

Such instability could affect network communication reliability and potentially lead to denial of service or other operational disruptions.

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