CVE-2026-63858 (GCVE-0-2026-63858)
Vulnerability from cvelistv5
Published
2026-07-19 14:04
Modified
2026-08-05 12:36
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: add hook transactions for device deletions Restore the flag that indicates that the hook is going away, ie. NFT_HOOK_REMOVE, but add a new transaction object to track deletion of hooks without altering the basechain/flowtable hook_list during the preparation phase. The existing approach that moves the hook from the basechain/flowtable hook_list to transaction hook_list breaks netlink dump path readers of this RCU-protected list. It should be possible use an array for nft_trans_hook to store the deleted hooks to compact the representation but I am not expecting many hook object, specially now that wildcard support for devices is in place. Note that the nft_trans_chain_hooks() list contains a list of struct nft_trans_hook objects for DELCHAIN and DELFLOWTABLE commands, while this list stores struct nft_hook objects for NEWCHAIN and NEWFLOWTABLE. Note that new commands can be updated to use nft_trans_hook for consistency. This patch also adapts the event notification path to deal with the list of hook transactions.
Impacted products
Vendor Product Version
Linux Linux Version: b6d9014a3335194590abdd2a2471ef5147a67645
Version: b6d9014a3335194590abdd2a2471ef5147a67645
Version: 7a248f9c74f9f62799718c12efd9e9e391d60b6f
Version: f275989ad04159dbfc62cefb65ba9c5ba1d7c34f
Version: 62d91062058b42bf70b2c3446aec397bb0ce15ee
Version: 99180dec5ae582227219d1fdd0dd5ccf53ec7491
Version: 5.10.122   
Version: 5.15.47   
Version: 5.17.15   
Version: 5.18.4   
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/net/netfilter/nf_tables.h",
            "net/netfilter/nf_tables_api.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
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              "status": "affected",
              "version": "b6d9014a3335194590abdd2a2471ef5147a67645",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "7a248f9c74f9f62799718c12efd9e9e391d60b6f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f275989ad04159dbfc62cefb65ba9c5ba1d7c34f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "62d91062058b42bf70b2c3446aec397bb0ce15ee",
              "versionType": "git"
            },
            {
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              "version": "99180dec5ae582227219d1fdd0dd5ccf53ec7491",
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            },
            {
              "lessThan": "5.11",
              "status": "affected",
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            },
            {
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              "version": "5.15.47",
              "versionType": "semver"
            },
            {
              "lessThan": "5.18",
              "status": "affected",
              "version": "5.17.15",
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            },
            {
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              "status": "affected",
              "version": "5.18.4",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/net/netfilter/nf_tables.h",
            "net/netfilter/nf_tables_api.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.19"
            },
            {
              "lessThan": "5.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.10",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.10.122",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.15.47",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.17.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.18.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: add hook transactions for device deletions\n\nRestore the flag that indicates that the hook is going away, ie.\nNFT_HOOK_REMOVE, but add a new transaction object to track deletion\nof hooks without altering the basechain/flowtable hook_list during\nthe preparation phase.\n\nThe existing approach that moves the hook from the basechain/flowtable\nhook_list to transaction hook_list breaks netlink dump path readers\nof this RCU-protected list.\n\nIt should be possible use an array for nft_trans_hook to store the\ndeleted hooks to compact the representation but I am not expecting\nmany hook object, specially now that wildcard support for devices\nis in place.\n\nNote that the nft_trans_chain_hooks() list contains a list of struct\nnft_trans_hook objects for DELCHAIN and DELFLOWTABLE commands, while\nthis list stores struct nft_hook objects for NEWCHAIN and NEWFLOWTABLE.\nNote that new commands can be updated to use nft_trans_hook for\nconsistency.\n\nThis patch also adapts the event notification path to deal with the list\nof hook transactions."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The vulnerability is reachable only through local Netlink syscalls to the nf_tables subsystem (NFT_MSG_DELCHAIN/DELFLOWTABLE hook deletion racing with GETCHAIN/GETFLOWTABLE dumps), which per kernel CNA guidance is Attack Vector Local, not network-reachable.\nAC:L - The attacker controls both sides of the race by opening concurrent Netlink sockets\u2014one issuing hook-deletion batch commands and another issuing chain/flowtable dumps\u2014making successful triggering reliably achievable without conditions outside attacker control.\nPR:L - All nf_tables Netlink operations require CAP_NET_ADMIN checked in nfnetlink_rcv(), which is obtainable by an unprivileged user via user namespaces (unshare -Urn), so privileges required are Low rather than High.\nUI:N - Exploitation requires no victim interaction; the attacker triggers the race entirely through their own concurrent Netlink requests without needing another user to perform any action.\nS:U - Impact remains within the kernel\u0027s security authority (kernel crash, memory corruption, potential local privilege escalation) rather than crossing a distinct security boundary such as VM guest-to-host escape.\nC:H - RCU list corruption yields a bogus nft_hook pointer that dereferences arbitrary kernel memory (e.g., reading hook-\u003eifname from stack-local or freed memory), constituting arbitrary kernel memory read potential consistent with High confidentiality impact.\nI:H - The corrupted list traversal produces invalid struct nft_hook pointers via container_of(), enabling heap/stack memory corruption that can be leveraged for arbitrary write or control-flow hijacking, warranting High integrity impact.\nA:H - The race reliably causes kernel oops/panic from dereferencing bogus nft_hook pointers during concurrent Netlink dumps, and the underlying RCU list corruption can crash or hang the system, giving High availability impact."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:36:37.055Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/4e69bfb32b2db323d9205fdb30e284481b37817c"
        },
        {
          "url": "https://git.kernel.org/stable/c/10f79dbd7719d1da9f5884d13060322d8729f091"
        }
      ],
      "title": "netfilter: nf_tables: add hook transactions for device deletions",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63858",
    "datePublished": "2026-07-19T14:04:46.967Z",
    "dateReserved": "2026-07-19T07:54:57.016Z",
    "dateUpdated": "2026-08-05T12:36:37.055Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
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