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7.5
HIGH CVSS 3.1
CVE-2026-53183
mptcp: allow subflow rcv wnd to shrink
Overview
Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: allow subflow rcv wnd to shrink In MPTCP connection, the `window` field in the TCP header refers to the MPTCP-level rcv_nxt and it's right edge should not move backward. Such constraint is enforced at DSS option generation time. At the same time, the TCP stack ensures independently that the TCP-level rcv wnd right's edge does not move backward. That in turn causes artificial inflating of the MPTCP rcv window when the incoming data is acked at the TCP level and is OoO in the MPTCP sequence space (or lands in the backlog). As a consequence, the incoming traffic can exceed the receiver rcvbuf size even when the sender is not misbehaving. Prevent such scenario forcibly allowing the TCP subflow to shrink the TCP-level rcv wnd regardless of the current netns setting.

Details
INFO

Published Date :

June 25, 2026, 9:16 a.m.

Last Modified :

July 6, 2026, 12:42 p.m.

Remotely Exploit :

Yes !

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Impact
Affected Products

The following products are affected by CVE-2026-53183 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
Allow subflow receive window to shrink to prevent receiver buffer overflow.
  • Update the Linux kernel to include the MPTCP fix.
  • Ensure netns settings do not prevent subflow window shrinking.
  • Monitor receiver buffer usage after the update.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-53183.

URL Resource
https://git.kernel.org/stable/c/653245266913f03fcf21cbca68eed5c197a33e52 Patch
https://git.kernel.org/stable/c/aa3861f40ac32706d9e97bfac76984613e278788 Patch
https://git.kernel.org/stable/c/b1fd13074f22105deec45aa02283e322733e0c2d Patch
https://git.kernel.org/stable/c/bf364b0f10b27679140699821f88af7f01e2a6e3 Patch
https://git.kernel.org/stable/c/c297a4e65c50a2b807d9309b22615080faffa8f3 Patch
https://git.kernel.org/stable/c/da23be77e1292cd611e736c3aa17da633d7ddce7 Patch
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-53183 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-53183 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-53183 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-53183 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Jul. 06, 2026

    Action Type Old Value New Value
    Added CWE NVD-CWE-noinfo
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.143 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.36 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.94 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.19 up to (excluding) 6.1.176 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.13 *cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:*
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/653245266913f03fcf21cbca68eed5c197a33e52 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/aa3861f40ac32706d9e97bfac76984613e278788 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/b1fd13074f22105deec45aa02283e322733e0c2d Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/bf364b0f10b27679140699821f88af7f01e2a6e3 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/c297a4e65c50a2b807d9309b22615080faffa8f3 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/da23be77e1292cd611e736c3aa17da633d7ddce7 Types: Patch
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jun. 28, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jun. 25, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'f3589be0c420a3137e5902d15705ced6a36f3f43', 'lessThan': 'bf364b0f10b27679140699821f88af7f01e2a6e3', 'versionType': 'git'}, {'status': 'affected', 'version': 'f3589be0c420a3137e5902d15705ced6a36f3f43', 'lessThan': 'b1fd13074f22105deec45aa02283e322733e0c2d', 'versionType': 'git'}, {'status': 'affected', 'version': 'f3589be0c420a3137e5902d15705ced6a36f3f43', 'lessThan': 'aa3861f40ac32706d9e97bfac76984613e278788', 'versionType': 'git'}, {'status': 'affected', 'version': 'f3589be0c420a3137e5902d15705ced6a36f3f43', 'lessThan': '653245266913f03fcf21cbca68eed5c197a33e52', 'versionType': 'git'}, {'status': 'affected', 'version': 'f3589be0c420a3137e5902d15705ced6a36f3f43', 'lessThan': 'c297a4e65c50a2b807d9309b22615080faffa8f3', 'versionType': 'git'}, {'status': 'affected', 'version': 'f3589be0c420a3137e5902d15705ced6a36f3f43', 'lessThan': 'da23be77e1292cd611e736c3aa17da633d7ddce7', 'versionType': 'git'}], 'programFiles': ['net/mptcp/options.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.19'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.19', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.1.176', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.143', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.94', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.36', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.13', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/mptcp/options.c'], 'defaultStatus': 'affected'}]
    Added Description In the Linux kernel, the following vulnerability has been resolved: mptcp: allow subflow rcv wnd to shrink In MPTCP connection, the `window` field in the TCP header refers to the MPTCP-level rcv_nxt and it's right edge should not move backward. Such constraint is enforced at DSS option generation time. At the same time, the TCP stack ensures independently that the TCP-level rcv wnd right's edge does not move backward. That in turn causes artificial inflating of the MPTCP rcv window when the incoming data is acked at the TCP level and is OoO in the MPTCP sequence space (or lands in the backlog). As a consequence, the incoming traffic can exceed the receiver rcvbuf size even when the sender is not misbehaving. Prevent such scenario forcibly allowing the TCP subflow to shrink the TCP-level rcv wnd regardless of the current netns setting.
    Added Reference https://git.kernel.org/stable/c/653245266913f03fcf21cbca68eed5c197a33e52
    Added Reference https://git.kernel.org/stable/c/aa3861f40ac32706d9e97bfac76984613e278788
    Added Reference https://git.kernel.org/stable/c/b1fd13074f22105deec45aa02283e322733e0c2d
    Added Reference https://git.kernel.org/stable/c/bf364b0f10b27679140699821f88af7f01e2a6e3
    Added Reference https://git.kernel.org/stable/c/c297a4e65c50a2b807d9309b22615080faffa8f3
    Added Reference https://git.kernel.org/stable/c/da23be77e1292cd611e736c3aa17da633d7ddce7
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 7.5
Attack Vector
Attack Complexity
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