CVE-2026-52998 (GCVE-0-2026-52998)
Vulnerability from cvelistv5
Published
2026-06-24 16:29
Modified
2026-08-05 12:32
Severity ?
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_osf: fix potential NULL dereference in ttl check The nf_osf_ttl() function accessed skb->dev to perform a local interface address lookup without verifying that the device pointer was valid. Additionally, the implementation utilized an in_dev_for_each_ifa_rcu loop to match the packet source address against local interface addresses. It assumed that packets from the same subnet should not see a decrement on the initial TTL. A packet might appear it is from the same subnet but it actually isn't especially in modern environments with containers and virtual switching. Remove the device dereference and interface loop. Replace the logic with a switch statement that evaluates the TTL according to the ttl_check.
References
Impacted products
Vendor Product Version
Linux Linux Version: 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384
Version: 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384
Version: 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384
Version: 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384
Version: 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384
Version: 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384
Version: 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384
Version: 11eeef41d5f63c7d2f7fdfcc733eb7fb137cc384
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/netfilter/nfnetlink_osf.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
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          "product": "Linux",
          "programFiles": [
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.31"
            },
            {
              "lessThan": "2.6.31",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.258",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.209",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.175",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "6.6.141",
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            {
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              "status": "unaffected",
              "version": "6.12.91",
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            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.33",
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              "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": "5.10.258",
                  "versionStartIncluding": "2.6.31",
                  "vulnerable": true
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "2.6.31",
                  "vulnerable": true
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.175",
                  "versionStartIncluding": "2.6.31",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.141",
                  "versionStartIncluding": "2.6.31",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.91",
                  "versionStartIncluding": "2.6.31",
                  "vulnerable": true
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                {
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                  "versionEndExcluding": "6.18.33",
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                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.10",
                  "versionStartIncluding": "2.6.31",
                  "vulnerable": true
                },
                {
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                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "2.6.31",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nfnetlink_osf: fix potential NULL dereference in ttl check\n\nThe nf_osf_ttl() function accessed skb-\u003edev to perform a local interface\naddress lookup without verifying that the device pointer was valid.\n\nAdditionally, the implementation utilized an in_dev_for_each_ifa_rcu\nloop to match the packet source address against local interface\naddresses. It assumed that packets from the same subnet should not see a\ndecrement on the initial TTL. A packet might appear it is from the same\nsubnet but it actually isn\u0027t especially in modern environments with\ncontainers and virtual switching.\n\nRemove the device dereference and interface loop. Replace the logic with\na switch statement that evaluates the TTL according to the ttl_check."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "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"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The vulnerable OSF match runs from IPv4 PRE_ROUTING/LOCAL_IN/FORWARD packet receive paths, and a remote TCP SYN can reach it on a firewall/bridge host using xt_osf or nft_osf.\nAC:L - There is no race or probabilistic condition; with OSF TTL_LESS active on a device lacking IPv4 configuration, the attacker can craft a SYN with TTL greater than the fingerprint TTL to trigger the NULL dereference reliably.\nPR:N - In the highest reasonable deployment, the OSF rule and fingerprints are already configured by the system, and the attacker only needs to send network traffic to the target.\nUI:N - No victim user action is needed; packet reception and netfilter rule evaluation trigger the bug automatically.\nS:U - The crash occurs within the same kernel/network filtering security authority and does not cross a VM, device-isolation, or sandbox boundary.\nC:N - The bug is a NULL pointer dereference of missing IPv4 device state, with no evidence of attacker-controlled memory disclosure.\nI:N - The vulnerable path does not provide a write primitive or data modification; it only dereferences NULL during TTL/local-address checking.\nA:H - The NULL dereference causes a kernel oops/panic in the packet receive path, producing a high-impact denial of service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:32:28.947Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f4de0777e4554a7de19c920accde6319dd530782"
        },
        {
          "url": "https://git.kernel.org/stable/c/c996a90f3071cf43683e5423da31aadbe002b8b4"
        },
        {
          "url": "https://git.kernel.org/stable/c/edc806f9122961f0d3819f7c69c14cccde31f277"
        },
        {
          "url": "https://git.kernel.org/stable/c/5d05de2f0928d81309a815ecc76d1a3ad72cbc16"
        },
        {
          "url": "https://git.kernel.org/stable/c/95be653a76793856ff8b2d8bd82c2943c23f5ca8"
        },
        {
          "url": "https://git.kernel.org/stable/c/79b90a96688e521771fa6ed3dc7864b76b8df293"
        },
        {
          "url": "https://git.kernel.org/stable/c/83fc5dd63455a779ea2dd0f7ffee3c920919d80b"
        },
        {
          "url": "https://git.kernel.org/stable/c/711987ba281fd806322a7cd244e98e2a81903114"
        }
      ],
      "title": "netfilter: nfnetlink_osf: fix potential NULL dereference in ttl check",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-52998",
    "datePublished": "2026-06-24T16:29:10.874Z",
    "dateReserved": "2026-06-09T07:44:35.377Z",
    "dateUpdated": "2026-08-05T12:32:28.947Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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