Vulnerability-Lookup

GHSA-WXVQ-PWV2-XPC3

Vulnerability from github – Published: 2026-06-25 09:31 – Updated: 2026-06-28 09:31

Details

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.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-53183"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-25T09:16:35Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: allow subflow rcv wnd to shrink\n\nIn MPTCP connection, the `window` field in the TCP header refers to the\nMPTCP-level rcv_nxt and it\u0027s right edge should not move backward. Such\nconstraint is enforced at DSS option generation time.\n\nAt the same time, the TCP stack ensures independently that the TCP-level\nrcv wnd right\u0027s edge does not move backward. That in turn causes artificial\ninflating of the MPTCP rcv window when the incoming data is acked at the\nTCP level and is OoO in the MPTCP sequence space (or lands in the backlog).\n\nAs a consequence, the incoming traffic can exceed the receiver rcvbuf size\neven when the sender is not misbehaving.\n\nPrevent such scenario forcibly allowing the TCP subflow to shrink the\nTCP-level rcv wnd regardless of the current netns setting.",
  "id": "GHSA-wxvq-pwv2-xpc3",
  "modified": "2026-06-28T09:31:43Z",
  "published": "2026-06-25T09:31:20Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53183"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/653245266913f03fcf21cbca68eed5c197a33e52"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/aa3861f40ac32706d9e97bfac76984613e278788"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b1fd13074f22105deec45aa02283e322733e0c2d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bf364b0f10b27679140699821f88af7f01e2a6e3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c297a4e65c50a2b807d9309b22615080faffa8f3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/da23be77e1292cd611e736c3aa17da633d7ddce7"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-53183 (GCVE-0-2026-53183)

Vulnerability from cvelistv5 – Published: 2026-06-25 08:38 – Updated: 2026-06-28 06:39

Title

mptcp: allow subflow rcv wnd to shrink

Summary

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.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Assigner

Linux

References

6 references

URL	Tags
https://git.kernel.org/stable/c/bf364b0f10b276791…
https://git.kernel.org/stable/c/b1fd13074f22105de…
https://git.kernel.org/stable/c/aa3861f40ac32706d…
https://git.kernel.org/stable/c/653245266913f03fc…
https://git.kernel.org/stable/c/c297a4e65c50a2b80…
https://git.kernel.org/stable/c/da23be77e1292cd61…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: f3589be0c420a3137e5902d15705ced6a36f3f43 , < bf364b0f10b27679140699821f88af7f01e2a6e3 (git) Affected: f3589be0c420a3137e5902d15705ced6a36f3f43 , < b1fd13074f22105deec45aa02283e322733e0c2d (git) Affected: f3589be0c420a3137e5902d15705ced6a36f3f43 , < aa3861f40ac32706d9e97bfac76984613e278788 (git) Affected: f3589be0c420a3137e5902d15705ced6a36f3f43 , < 653245266913f03fcf21cbca68eed5c197a33e52 (git) Affected: f3589be0c420a3137e5902d15705ced6a36f3f43 , < c297a4e65c50a2b807d9309b22615080faffa8f3 (git) Affected: f3589be0c420a3137e5902d15705ced6a36f3f43 , < da23be77e1292cd611e736c3aa17da633d7ddce7 (git)
Linux	Linux	Affected: 5.19 Unaffected: 0 , < 5.19 (semver) Unaffected: 6.1.176 , ≤ 6.1.* (semver) Unaffected: 6.6.143 , ≤ 6.6.* (semver) Unaffected: 6.12.94 , ≤ 6.12.* (semver) Unaffected: 6.18.36 , ≤ 6.18.* (semver) Unaffected: 7.0.13 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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    "cna": {
      "affected": [
        {
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          "programFiles": [
            "net/mptcp/options.c"
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              "versionType": "semver"
            },
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              "status": "unaffected",
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        }
      ],
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
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        "dateUpdated": "2026-06-28T06:39:57.040Z",
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        {
          "url": "https://git.kernel.org/stable/c/da23be77e1292cd611e736c3aa17da633d7ddce7"
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    "datePublished": "2026-06-25T08:38:57.443Z",
    "dateReserved": "2026-06-09T07:44:35.390Z",
    "dateUpdated": "2026-06-28T06:39:57.040Z",
    "state": "PUBLISHED"
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

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GHSA-WXVQ-PWV2-XPC3

CVE-2026-53183 (GCVE-0-2026-53183)

Tags

Sightings

Nomenclature