Vulnerability-Lookup

FKIE_CVE-2026-74475

Vulnerability from fkie_nvd - Published: 2026-08-15 13:17 - Updated: 2026-08-17 06:19

Severity

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

Summary

In the Linux kernel, the following vulnerability has been resolved: vxlan: use neigh_ha_snapshot() in route_shortcircuit() The neighbour hardware address n->ha can be updated asynchronously by the neighbour subsystem, protected by n->ha_lock seqlock. Reading n->ha without holding the seqlock loop can lead to torn reads or reading a partially updated MAC address. Use neigh_ha_snapshot() in route_shortcircuit() to safely copy n->ha under read_seqbegin()/read_seqretry() lock protection before using it. Note that arp_reduce() and neigh_reduce() seem to have the same issue left for future patches.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/05f2987f73daa05333fd713d05546142f9f7c5f0
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/8eca411347e1d38964f9ed2c8d3b6ab0e7e4473d
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d08e8ac13f2e228cc7fc3c70b5ebe71557b624a0
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ec341bb76d77b4c2948764375ee6bfeef4bb41c3
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ff89415d34c3ab9f5312316423122e664ed3524f

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/vxlan/vxlan_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "d08e8ac13f2e228cc7fc3c70b5ebe71557b624a0",
              "status": "affected",
              "version": "e4f67addf158f98f8197e08974966b18480dc751",
              "versionType": "git"
            },
            {
              "lessThan": "ec341bb76d77b4c2948764375ee6bfeef4bb41c3",
              "status": "affected",
              "version": "e4f67addf158f98f8197e08974966b18480dc751",
              "versionType": "git"
            },
            {
              "lessThan": "ff89415d34c3ab9f5312316423122e664ed3524f",
              "status": "affected",
              "version": "e4f67addf158f98f8197e08974966b18480dc751",
              "versionType": "git"
            },
            {
              "lessThan": "05f2987f73daa05333fd713d05546142f9f7c5f0",
              "status": "affected",
              "version": "e4f67addf158f98f8197e08974966b18480dc751",
              "versionType": "git"
            },
            {
              "lessThan": "8eca411347e1d38964f9ed2c8d3b6ab0e7e4473d",
              "status": "affected",
              "version": "e4f67addf158f98f8197e08974966b18480dc751",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/vxlan/vxlan_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.8"
            },
            {
              "lessThan": "3.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.151",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.103",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: use neigh_ha_snapshot() in route_shortcircuit()\n\nThe neighbour hardware address n-\u003eha can be updated asynchronously by the\nneighbour subsystem, protected by n-\u003eha_lock seqlock. Reading n-\u003eha without\nholding the seqlock loop can lead to torn reads or reading a partially updated\nMAC address.\n\nUse neigh_ha_snapshot() in route_shortcircuit() to safely copy n-\u003eha under\nread_seqbegin()/read_seqretry() lock protection before using it.\n\nNote that arp_reduce() and neigh_reduce() seem to have the same issue\nleft for future patches."
    }
  ],
  "id": "CVE-2026-74475",
  "lastModified": "2026-08-17T06:19:43.543",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 10.0,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 6.0,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-15T13:17:52.293",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/05f2987f73daa05333fd713d05546142f9f7c5f0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8eca411347e1d38964f9ed2c8d3b6ab0e7e4473d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d08e8ac13f2e228cc7fc3c70b5ebe71557b624a0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ec341bb76d77b4c2948764375ee6bfeef4bb41c3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ff89415d34c3ab9f5312316423122e664ed3524f"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-74475 (GCVE-0-2026-74475)

Vulnerability from cvelistv5 – Published: 2026-08-15 12:27 – Updated: 2026-08-17 05:47

Title

vxlan: use neigh_ha_snapshot() in route_shortcircuit()

Summary

Severity

10 (Critical)


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

Assigner

Linux mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/d08e8ac13f2e228cc…
https://git.kernel.org/stable/c/ec341bb76d77b4c29…
https://git.kernel.org/stable/c/ff89415d34c3ab9f5…
https://git.kernel.org/stable/c/05f2987f73daa0533…
https://git.kernel.org/stable/c/8eca411347e1d3896…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: e4f67addf158f98f8197e08974966b18480dc751 , < d08e8ac13f2e228cc7fc3c70b5ebe71557b624a0 (git) Affected: e4f67addf158f98f8197e08974966b18480dc751 , < ec341bb76d77b4c2948764375ee6bfeef4bb41c3 (git) Affected: e4f67addf158f98f8197e08974966b18480dc751 , < ff89415d34c3ab9f5312316423122e664ed3524f (git) Affected: e4f67addf158f98f8197e08974966b18480dc751 , < 05f2987f73daa05333fd713d05546142f9f7c5f0 (git) Affected: e4f67addf158f98f8197e08974966b18480dc751 , < 8eca411347e1d38964f9ed2c8d3b6ab0e7e4473d (git)
Linux	Linux	Affected: 3.8 Unaffected: 0 , < 3.8 (semver) Unaffected: 6.6.151 , ≤ 6.6.* (semver) Unaffected: 6.12.103 , ≤ 6.12.* (semver) Unaffected: 6.18.44 , ≤ 6.18.* (semver) Unaffected: 7.1.8 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/vxlan/vxlan_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "d08e8ac13f2e228cc7fc3c70b5ebe71557b624a0",
              "status": "affected",
              "version": "e4f67addf158f98f8197e08974966b18480dc751",
              "versionType": "git"
            },
            {
              "lessThan": "ec341bb76d77b4c2948764375ee6bfeef4bb41c3",
              "status": "affected",
              "version": "e4f67addf158f98f8197e08974966b18480dc751",
              "versionType": "git"
            },
            {
              "lessThan": "ff89415d34c3ab9f5312316423122e664ed3524f",
              "status": "affected",
              "version": "e4f67addf158f98f8197e08974966b18480dc751",
              "versionType": "git"
            },
            {
              "lessThan": "05f2987f73daa05333fd713d05546142f9f7c5f0",
              "status": "affected",
              "version": "e4f67addf158f98f8197e08974966b18480dc751",
              "versionType": "git"
            },
            {
              "lessThan": "8eca411347e1d38964f9ed2c8d3b6ab0e7e4473d",
              "status": "affected",
              "version": "e4f67addf158f98f8197e08974966b18480dc751",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/vxlan/vxlan_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.8"
            },
            {
              "lessThan": "3.8",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.151",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.103",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.44",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "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": "6.6.151",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.103",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.44",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.8",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "3.8",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: use neigh_ha_snapshot() in route_shortcircuit()\n\nThe neighbour hardware address n-\u003eha can be updated asynchronously by the\nneighbour subsystem, protected by n-\u003eha_lock seqlock. Reading n-\u003eha without\nholding the seqlock loop can lead to torn reads or reading a partially updated\nMAC address.\n\nUse neigh_ha_snapshot() in route_shortcircuit() to safely copy n-\u003eha under\nread_seqbegin()/read_seqretry() lock protection before using it.\n\nNote that arp_reduce() and neigh_reduce() seem to have the same issue\nleft for future patches."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 10,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - route_shortcircuit() runs on the vxlan_xmit() transmit path when overlay IP/IPv6 traffic is encapsulated; in cloud/SDN VTEP deployments a remote tenant can drive dev_queue_xmit() through bridge/IP forwarding without any local syscall or netlink access.\nAC:L - The attacker controls both sides of the race by concurrently sending overlay traffic that hits route_shortcircuit() and generating neighbour ha updates (ARP/NDP churn); repeated attempts do not depend on victim state or uncontrollable memory layout.\nPR:N - Exploitation requires only the ability to send overlay/underlay packets to a VTEP that already has VXLAN_F_RSC and router FDB entries configured by infrastructure; no CAP_NET_ADMIN, root, or host credentials are needed on the victim.\nUI:N - Triggering is automatic during kernel packet forwarding and VXLAN encapsulation once matching traffic flows; no mount, file open, or other victim action is required beyond normal overlay operation.\nS:C - A torn n-\u003eha read can rewrite the skb Ethernet destination and reselect a different FDB remote, mis-encapsulating traffic to an unintended VXLAN peer and crossing intended multi-tenant overlay segmentation boundaries beyond the local VTEP authority.\nC:H - Unsynchronized reads of neighbour ha during concurrent updates yield torn MAC values that drive post-rewrite FDB lookup and encapsulation, potentially delivering other tenants\u0027 overlay frames to an attacker-controlled remote endpoint or leaking mixed neighbour state.\nI:H - The corrupted hardware address is copied into the skb Ethernet header and steers subsequent vxlan_find_mac_tx()/vxlan_xmit_one() encapsulation, enabling deterministic overlay traffic redirection or injection toward an attacker-chosen VTEP rather than the intended router destination.\nA:L - While the host kernel does not panic, torn MAC rewriting can cause mis-encapsulation, FDB misses, and dropped or misdelivered overlay packets, producing intermittent connectivity loss and performance degradation on affected VTEP nodes under sustained attack."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:47:36.362Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/d08e8ac13f2e228cc7fc3c70b5ebe71557b624a0"
        },
        {
          "url": "https://git.kernel.org/stable/c/ec341bb76d77b4c2948764375ee6bfeef4bb41c3"
        },
        {
          "url": "https://git.kernel.org/stable/c/ff89415d34c3ab9f5312316423122e664ed3524f"
        },
        {
          "url": "https://git.kernel.org/stable/c/05f2987f73daa05333fd713d05546142f9f7c5f0"
        },
        {
          "url": "https://git.kernel.org/stable/c/8eca411347e1d38964f9ed2c8d3b6ab0e7e4473d"
        }
      ],
      "title": "vxlan: use neigh_ha_snapshot() in route_shortcircuit()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74475",
    "datePublished": "2026-08-15T12:27:10.685Z",
    "dateReserved": "2026-08-15T05:44:03.903Z",
    "dateUpdated": "2026-08-17T05:47:36.362Z",
    "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.

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FKIE_CVE-2026-74475

CVE-2026-74475 (GCVE-0-2026-74475)

Tags

Sightings

Nomenclature