Vulnerability-Lookup

FKIE_CVE-2026-31685

Vulnerability from fkie_nvd - Published: 2026-04-25 09:16 - Updated: 2026-06-17 10:34

Severity

9.4 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: ip6t_eui64: reject invalid MAC header for all packets `eui64_mt6()` derives a modified EUI-64 from the Ethernet source address and compares it with the low 64 bits of the IPv6 source address. The existing guard only rejects an invalid MAC header when `par->fragoff != 0`. For packets with `par->fragoff == 0`, `eui64_mt6()` can still reach `eth_hdr(skb)` even when the MAC header is not valid. Fix this by removing the `par->fragoff != 0` condition so that packets with an invalid MAC header are rejected before accessing `eth_hdr(skb)`.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/288138418bef956f8b295751a4536c60f0e89f4a	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/309ae3e9a51a69699ca94eac5fac5688fa562d55	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/4d75bc2cd093bf5803edf512c099bfb220fd6459
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/7d6a57411caf54df025860c9b1a82cd42d57a562
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/807d6ee15804df6f01a35c910f09612e858739a6	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/9eda5478746ef7dc0e4e537b5a5e4b0ca1027091	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d5603591373441fecf9951833d6d873e09320f08
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/fdce0b3590f724540795b874b4c8850c90e6b0a8	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	2.6.12
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/netfilter/ip6t_eui64.c"
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          "vendor": "Linux",
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              "versionType": "git"
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              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
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              "status": "affected",
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          "programFiles": [
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          ],
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          "vendor": "Linux",
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              "version": "2.6.12"
            },
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              "version": "0",
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            {
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              "status": "unaffected",
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              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "5.15.209",
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            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.175",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.136",
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            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.83",
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            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.24",
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            },
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              "status": "unaffected",
              "version": "6.19.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "E2D9D9DF-0F25-43D5-9C6A-4C891E3A29FC",
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            },
            {
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              "matchCriteriaId": "6F62EECE-8FB1-4D57-85D8-CB9E23CF313C",
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              "vulnerable": true
            },
            {
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              "vulnerable": true
            },
            {
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              "matchCriteriaId": "476CB3A5-D022-4F13-AAEF-CB6A5785516A",
              "vulnerable": true
            },
            {
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              "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*",
              "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64",
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            },
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            },
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              "vulnerable": true
            },
            {
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              "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6",
              "vulnerable": true
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            {
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              "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138",
              "vulnerable": true
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          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ip6t_eui64: reject invalid MAC header for all packets\n\n`eui64_mt6()` derives a modified EUI-64 from the Ethernet source address\nand compares it with the low 64 bits of the IPv6 source address.\n\nThe existing guard only rejects an invalid MAC header when\n`par-\u003efragoff != 0`. For packets with `par-\u003efragoff == 0`, `eui64_mt6()`\ncan still reach `eth_hdr(skb)` even when the MAC header is not valid.\n\nFix this by removing the `par-\u003efragoff != 0` condition so that packets\nwith an invalid MAC header are rejected before accessing `eth_hdr(skb)`."
    }
  ],
  "id": "CVE-2026-31685",
  "lastModified": "2026-06-17T10:34:14.193",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.4,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.5,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-04-25T09:16:02.273",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/288138418bef956f8b295751a4536c60f0e89f4a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/309ae3e9a51a69699ca94eac5fac5688fa562d55"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4d75bc2cd093bf5803edf512c099bfb220fd6459"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7d6a57411caf54df025860c9b1a82cd42d57a562"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/807d6ee15804df6f01a35c910f09612e858739a6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/9eda5478746ef7dc0e4e537b5a5e4b0ca1027091"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d5603591373441fecf9951833d6d873e09320f08"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/fdce0b3590f724540795b874b4c8850c90e6b0a8"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-31685 (GCVE-0-2026-31685)

Vulnerability from cvelistv5 – Published: 2026-04-25 08:47 – Updated: 2026-08-05 12:24

Title

netfilter: ip6t_eui64: reject invalid MAC header for all packets

Summary

Severity

9.4 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H

Assigner

Linux mitre root

References

8 references

URL	Tags
https://git.kernel.org/stable/c/4d75bc2cd093bf580…
https://git.kernel.org/stable/c/7d6a57411caf54df0…
https://git.kernel.org/stable/c/d5603591373441fec…
https://git.kernel.org/stable/c/288138418bef956f8…
https://git.kernel.org/stable/c/9eda5478746ef7dc0…
https://git.kernel.org/stable/c/807d6ee15804df6f0…
https://git.kernel.org/stable/c/309ae3e9a51a69699…
https://git.kernel.org/stable/c/fdce0b3590f724540…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 4d75bc2cd093bf5803edf512c099bfb220fd6459 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 7d6a57411caf54df025860c9b1a82cd42d57a562 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < d5603591373441fecf9951833d6d873e09320f08 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 288138418bef956f8b295751a4536c60f0e89f4a (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 9eda5478746ef7dc0e4e537b5a5e4b0ca1027091 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 807d6ee15804df6f01a35c910f09612e858739a6 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 309ae3e9a51a69699ca94eac5fac5688fa562d55 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < fdce0b3590f724540795b874b4c8850c90e6b0a8 (git)
Linux	Linux	Affected: 2.6.12 Unaffected: 0 , < 2.6.12 (semver) Unaffected: 5.10.258 , ≤ 5.10.* (semver) Unaffected: 5.15.209 , ≤ 5.15.* (semver) Unaffected: 6.1.175 , ≤ 6.1.* (semver) Unaffected: 6.6.136 , ≤ 6.6.* (semver) Unaffected: 6.12.83 , ≤ 6.12.* (semver) Unaffected: 6.18.24 , ≤ 6.18.* (semver) Unaffected: 6.19.14 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/netfilter/ip6t_eui64.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4d75bc2cd093bf5803edf512c099bfb220fd6459",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "7d6a57411caf54df025860c9b1a82cd42d57a562",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "d5603591373441fecf9951833d6d873e09320f08",
              "status": "affected",
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              "versionType": "git"
            },
            {
              "lessThan": "288138418bef956f8b295751a4536c60f0e89f4a",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "9eda5478746ef7dc0e4e537b5a5e4b0ca1027091",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "807d6ee15804df6f01a35c910f09612e858739a6",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "309ae3e9a51a69699ca94eac5fac5688fa562d55",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
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              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv6/netfilter/ip6t_eui64.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.12"
            },
            {
              "lessThan": "2.6.12",
              "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"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.136",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.83",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.24",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.258",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.209",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.175",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.136",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.83",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.24",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.14",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "2.6.12",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ip6t_eui64: reject invalid MAC header for all packets\n\n`eui64_mt6()` derives a modified EUI-64 from the Ethernet source address\nand compares it with the low 64 bits of the IPv6 source address.\n\nThe existing guard only rejects an invalid MAC header when\n`par-\u003efragoff != 0`. For packets with `par-\u003efragoff == 0`, `eui64_mt6()`\ncan still reach `eth_hdr(skb)` even when the MAC header is not valid.\n\nFix this by removing the `par-\u003efragoff != 0` condition so that packets\nwith an invalid MAC header are rejected before accessing `eth_hdr(skb)`."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.4,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The vulnerable match runs from IPv6 netfilter PREROUTING/LOCAL_IN/FORWARD packet hooks, so a remote peer can reach it by sending IPv6 traffic to or through a host/router with an active eui64 xtables rule on a path with an invalid or absent Ethernet MAC header.\nAC:L - There is no race or timing requirement; the attacker can send first-fragment or non-fragment IPv6 packets with controlled header fields, and the active rule/interface combination is a deployment precondition.\nPR:N - Although installing the rule requires CAP_NET_ADMIN, in the highest-severity reasonable deployment the eui64 rule is already active and unauthenticated packets trigger the vulnerable packet path without attacker privileges.\nUI:N - No victim action is needed after the affected netfilter rule is present; packet delivery alone invokes the match.\nS:U - The impact remains within the kernel/networking security authority of the affected system and does not cross a VM, IOMMU, or similar boundary.\nC:H - With an unset or invalid MAC header, eth_hdr() can read outside the valid Ethernet header area and those bytes can influence observable netfilter behavior; following the required conservative rule for out-of-bounds reads, confidentiality is High.\nI:L - The bug can cause invalid-L2 packets to satisfy an eui64 match and bypass filtering decisions based on Ethernet-source-to-IPv6-source binding, but it does not provide a direct kernel write primitive.\nA:H - Invalid eth_hdr() access on packets with no valid MAC header can produce kernel warnings/oopses or KASAN-detected out-of-bounds accesses, and an attacker can repeat packet delivery to sustain denial of service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:24:29.973Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/4d75bc2cd093bf5803edf512c099bfb220fd6459"
        },
        {
          "url": "https://git.kernel.org/stable/c/7d6a57411caf54df025860c9b1a82cd42d57a562"
        },
        {
          "url": "https://git.kernel.org/stable/c/d5603591373441fecf9951833d6d873e09320f08"
        },
        {
          "url": "https://git.kernel.org/stable/c/288138418bef956f8b295751a4536c60f0e89f4a"
        },
        {
          "url": "https://git.kernel.org/stable/c/9eda5478746ef7dc0e4e537b5a5e4b0ca1027091"
        },
        {
          "url": "https://git.kernel.org/stable/c/807d6ee15804df6f01a35c910f09612e858739a6"
        },
        {
          "url": "https://git.kernel.org/stable/c/309ae3e9a51a69699ca94eac5fac5688fa562d55"
        },
        {
          "url": "https://git.kernel.org/stable/c/fdce0b3590f724540795b874b4c8850c90e6b0a8"
        }
      ],
      "title": "netfilter: ip6t_eui64: reject invalid MAC header for all packets",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31685",
    "datePublished": "2026-04-25T08:47:02.857Z",
    "dateReserved": "2026-03-09T15:48:24.131Z",
    "dateUpdated": "2026-08-05T12:24:29.973Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.