---
id: CVE-2026-80588
title: 'mptcp: reclaim forward-allocated memory on RX path errors'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  mptcp: reclaim forward-allocated memory on RX path errors

  After commit 9db5b3cec4ec ("mptcp: borrow forward memory from subflow"),
  errors in the receive path prior to …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= a84164847b1e0a106ebc46821e5d2f9b775c9dc8 <
    473f1a5ab2abc98dd9e74b95b9c23c66c47535cc
  - >-
    Linux >= 9db5b3cec4ec1c0cd3239689f5c8653d691a1754 <
    8277f48a06d3aa1441f6d0b6998ccc0360d30ed8
  - >-
    Linux >= 9db5b3cec4ec1c0cd3239689f5c8653d691a1754 <
    41b49a8b914ec7dcb03eae93fb27f3c464078644
  - Linux >= 6.18.35 < 6.18.46
  - Linux 6.19
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-16T19:18:06.349693Z'
published: '2026-08-26'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T19:26:28.920Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-80588'
references:
  - url: 'https://git.kernel.org/stable/c/473f1a5ab2abc98dd9e74b95b9c23c66c47535cc'
  - url: 'https://git.kernel.org/stable/c/8277f48a06d3aa1441f6d0b6998ccc0360d30ed8'
  - url: 'https://git.kernel.org/stable/c/41b49a8b914ec7dcb03eae93fb27f3c464078644'
tags:
  - cve.org
epss: 0.00609
epssPercentile: 0.48057
ingestedAt: '2026-10-16T19:46:24.311Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

mptcp: reclaim forward-allocated memory on RX path errors

After commit 9db5b3cec4ec ("mptcp: borrow forward memory from subflow"),
errors in the receive path prior to queueing skbs into the receive
queue do not trigger forward-allocated memory reclaiming.

Prevent forward memory from growing unboundedly in pathological drop
scenarios by explicitly reclaiming memory when skbs are dropped.

## Affected

- `Linux >= a84164847b1e0a106ebc46821e5d2f9b775c9dc8 < 473f1a5ab2abc98dd9e74b95b9c23c66c47535cc`
- `Linux >= 9db5b3cec4ec1c0cd3239689f5c8653d691a1754 < 8277f48a06d3aa1441f6d0b6998ccc0360d30ed8`
- `Linux >= 9db5b3cec4ec1c0cd3239689f5c8653d691a1754 < 41b49a8b914ec7dcb03eae93fb27f3c464078644`
- `Linux >= 6.18.35 < 6.18.46`
- `Linux 6.19`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.