{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-80588",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-80588"
  ],
  "published": "2026-08-26T14:37:59Z",
  "summary": "mptcp: reclaim forward-allocated memory on RX path errors",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: reclaim forward-allocated memory on RX path errors\n\nAfter commit 9db5b3cec4ec (\"mptcp: borrow forward memory from subflow\"),\nerrors in the receive path prior to queueing skbs into the receive\nqueue do not trigger forward-allocated memory reclaiming.\n\nPrevent forward memory from growing unboundedly in pathological drop\nscenarios by explicitly reclaiming memory when skbs are dropped.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:13",
        "name": "linux"
      },
      "versions": [
        "1:6.18.39-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.18.39+rpt-rpi-2712",
            "binary_version": "1:6.18.39-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.39+rpt-rpi-v8",
            "binary_version": "1:6.18.39-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.39+rpt-rpi-v8-rt",
            "binary_version": "1:6.18.39-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.18.39-1+rpt1": {
            "linux_commit": "60ea684a8ace97bb0db1a16e20753bdd6ab371ff",
            "upstream_version": "6.18.39",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.18.46"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-80588"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/473f1a5ab2abc98dd9e74b95b9c23c66c47535cc"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8277f48a06d3aa1441f6d0b6998ccc0360d30ed8"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/41b49a8b914ec7dcb03eae93fb27f3c464078644"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-27T05:18:36Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.5,
      "cvss_v3_severity": "High",
      "scenario": "AV:N - Remote TCP/MPTCP peers reach the bug on the established-connection RX datapath (tcp_rcv_established \u2192 subflow_data_ready \u2192 mptcp_data_ready \u2192 __mptcp_move_skbs_from_subflow \u2192 __mptcp_move_skb \u2192 mptcp_drop) when duplicate or out-of-window mapped data is dropped before skb_set_owner_r().\nAC:L - The attacker fully controls subflow packet contents and ordering on their MPTCP connection and can deterministically trigger drops (duplicate map_seq, OoO beyond rcv_wnd) on every crafted segment without races, rare sysctl state, or uncontrollable memory layout.\nPR:N - No local account or kernel capability is required on the victim; any remote peer that completes the TCP/MPTCP handshake on an IPPROTO_MPTCP socket (Android clients, MPTCP-enabled servers, curl --mptcp) can flood pathological RX drops without target credentials.\nUI:N - Exploitation needs only attacker-generated MPTCP/TCP traffic on an existing or attacker-initiated connection; no victim mount, file open, click, or other cooperative user action beyond normal network stack processing.\nS:U - Impact is unbounded sk_forward_alloc growth and kernel memory exhaustion on the affected host; it does not cross VM, container, IOMMU, or sandbox boundaries to another security authority.\nC:N - This is a forward-memory accounting leak on skb drop after mptcp_borrow_fwdmem(); skb data is freed and no use-after-free, out-of-bounds read, or other memory-corruption primitive exposes kernel contents to the attacker.\nI:N - The flaw only fails to reclaim borrowed forward allocation when dropping skbs; it does not corrupt, overwrite, or modify attacker-chosen memory and provides no write or code-execution primitive.\nA:H - Each pre-queue drop leaks roughly skb->truesize forward memory while bypassing the removed sk_rmem_schedule guard, so a remote peer can repeatedly trigger unbounded per-connection kernel memory growth and OOM denial of service, matching CNA precedent for repeatable network skb/memory leaks."
    }
  }
}