CVE-2026-64410 (GCVE-0-2026-64410)
Vulnerability from cvelistv5
Published
2026-07-25 08:50
Modified
2026-08-17 04:55
Severity ?
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: IPIP tunnel hardware offload is not yet support No driver supports for IPIP tunnels yet, give up early on setting up the hardware offload for this scenario. This patch adds a stub that can be enhanced to add more configuration that are currently not supported. As of now, the offload work is enqueued to the worker, then ignored if the hardware offload configuration is not supported. Check the NF_FLOW_HW flag to know if this entry was already tried once to be offloaded so this is not retried on refresh when unsupported. Move NF_FLOW_HW flag check to nf_flow_offload_add(). If this NF_FLOW_HW flag is unset the _del and _stats variants are never called. This can be updated later on to skip hardware offload work to be queued in case hardware offload does not support it.
References
Impacted products
Vendor Product Version
Linux Linux Version: ab427db17885814069bae891834f20842f0ac3a4
Version: ab427db17885814069bae891834f20842f0ac3a4
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/netfilter/nf_flow_table.h",
            "net/netfilter/nf_flow_table_core.c",
            "net/netfilter/nf_flow_table_offload.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "9efe838c13133acb70c78d04c49e8362fe533566",
              "status": "affected",
              "version": "ab427db17885814069bae891834f20842f0ac3a4",
              "versionType": "git"
            },
            {
              "lessThan": "6c5dcab95f4cd42a1648739ec9300fbb4b1a021f",
              "status": "affected",
              "version": "ab427db17885814069bae891834f20842f0ac3a4",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/net/netfilter/nf_flow_table.h",
            "net/netfilter/nf_flow_table_core.c",
            "net/netfilter/nf_flow_table_offload.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.19"
            },
            {
              "lessThan": "6.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.4",
                  "versionStartIncluding": "6.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.19",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: flowtable: IPIP tunnel hardware offload is not yet support\n\nNo driver supports for IPIP tunnels yet, give up early on setting up the\nhardware offload for this scenario.\n\nThis patch adds a stub that can be enhanced to add more configuration\nthat are currently not supported. As of now, the offload work is\nenqueued to the worker, then ignored if the hardware offload\nconfiguration is not supported.\n\nCheck the NF_FLOW_HW flag to know if this entry was already tried once\nto be offloaded so this is not retried on refresh when unsupported. Move\nNF_FLOW_HW flag check to nf_flow_offload_add(). If this NF_FLOW_HW flag\nis unset the _del and _stats variants are never called.\n\nThis can be updated later on to skip hardware offload work to be queued\nin case hardware offload does not support it."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - On a router with an IPIP tunnel and hardware-enabled nftables flowtable, remote TCP or UDP traffic reaches nft_flow_offload_eval and causes the unsupported hardware-offload work. No local syscall access is required from the attacker.\nAC:L - Once the affected deployment is configured, confirmed attacker-controlled flows reliably trigger rule generation and refresh retries without a race or other condition outside the attacker\u0027s control.\nPR:N - Creating the tunnel and flowtable requires CAP_NET_ADMIN, but these are deployment prerequisites; an attacker sending traffic through an already configured router needs no privileges or authentication.\nUI:N - Packet processing and hardware-rule installation occur automatically without any victim user action.\nS:U - The vulnerable netfilter logic and the affected forwarding, driver, and kernel resources remain under the same kernel security authority.\nC:H - The generated hardware rules omit the IPIP outer-match and encapsulation semantics, potentially forwarding complete inner-flow contents outside the intended tunnel isolation and onto an unintended network.\nI:H - A false hardware rule can match spoofed plain inner packets on physical ingress and redirect them as though they were properly decapsulated, bypassing software netfilter and enabling attacker-chosen payload injection.\nA:H - Attackers can create many eligible flows, causing repeated unsupported offload work and consumption of driver or hardware rule resources. Incorrectly accepted rules can also blackhole tunnel traffic, permitting sustained loss of network service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:55:08.961Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/9efe838c13133acb70c78d04c49e8362fe533566"
        },
        {
          "url": "https://git.kernel.org/stable/c/6c5dcab95f4cd42a1648739ec9300fbb4b1a021f"
        }
      ],
      "title": "netfilter: flowtable: IPIP tunnel hardware offload is not yet support",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64410",
    "datePublished": "2026-07-25T08:50:51.377Z",
    "dateReserved": "2026-07-19T15:36:31.786Z",
    "dateUpdated": "2026-08-17T04:55:08.961Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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