Vulnerability-Lookup

FKIE_CVE-2026-80838

Vulnerability from fkie_nvd - Published: 2026-09-04 16:18 - Updated: 2026-09-04 16:18

Severity

Summary

In the Linux kernel, the following vulnerability has been resolved: vxlan: keep the last remote linked during FDB flush A non-nexthop FDB entry is expected to have at least one remote while it remains reachable through the FDB hash table. A filtered bulk flush violates this invariant when every remote matches: It unlinks the last remote in vxlan_fdb_dst_destroy() and only afterwards tells vxlan_flush() to destroy the parent FDB entry. An RCU reader can find the parent during this interval. first_remote_rcu() then applies list_entry_rcu() to the empty list head, producing an invalid remote pointer that the receive learning path can read from and write to. When a matching remote is the sole remaining remote, leave it linked and ask the caller to destroy the entire FDB entry. vxlan_fdb_destroy() keeps the remote attached while sending the deletion notification and removing the parent from the lookup structures.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/2a7c2f00843225d5f037676bca649321f3d024c7
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/a8820c8a7718327e96849782033e7c85a0f6bcfe
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d5d4a7b538b52db63927773a8905fcd9f78a42e2

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": "2a7c2f00843225d5f037676bca649321f3d024c7",
              "status": "affected",
              "version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
              "versionType": "git"
            },
            {
              "lessThan": "a8820c8a7718327e96849782033e7c85a0f6bcfe",
              "status": "affected",
              "version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
              "versionType": "git"
            },
            {
              "lessThan": "8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c",
              "status": "affected",
              "version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
              "versionType": "git"
            },
            {
              "lessThan": "4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab",
              "status": "affected",
              "version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
              "versionType": "git"
            },
            {
              "lessThan": "d5d4a7b538b52db63927773a8905fcd9f78a42e2",
              "status": "affected",
              "version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
              "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": "6.7"
            },
            {
              "lessThan": "6.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.108",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.49",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "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: keep the last remote linked during FDB flush\n\nA non-nexthop FDB entry is expected to have at least one remote while it\nremains reachable through the FDB hash table. A filtered bulk flush\nviolates this invariant when every remote matches: It unlinks the last\nremote in vxlan_fdb_dst_destroy() and only afterwards tells vxlan_flush()\nto destroy the parent FDB entry.\n\nAn RCU reader can find the parent during this interval.\nfirst_remote_rcu() then applies list_entry_rcu() to the empty list head,\nproducing an invalid remote pointer that the receive learning path can\nread from and write to.\n\nWhen a matching remote is the sole remaining remote, leave it linked and\nask the caller to destroy the entire FDB entry. vxlan_fdb_destroy() keeps\nthe remote attached while sending the deletion notification and removing\nthe parent from the lookup structures."
    }
  ],
  "id": "CVE-2026-80838",
  "lastModified": "2026-09-04T16:18:12.183",
  "metrics": {},
  "published": "2026-09-04T16:18:12.183",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2a7c2f00843225d5f037676bca649321f3d024c7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a8820c8a7718327e96849782033e7c85a0f6bcfe"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d5d4a7b538b52db63927773a8905fcd9f78a42e2"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-80838 (GCVE-0-2026-80838)

Vulnerability from cvelistv5 – Published: 2026-09-04 15:54 – Updated: 2026-09-04 15:54

Title

vxlan: keep the last remote linked during FDB flush

Summary

Severity

No CVSS data available.

Assigner

Linux mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/2a7c2f00843225d5f…
https://git.kernel.org/stable/c/a8820c8a7718327e9…
https://git.kernel.org/stable/c/8ba68fd6cdd1e3c92…
https://git.kernel.org/stable/c/4bbc76ee1b21d3bd0…
https://git.kernel.org/stable/c/d5d4a7b538b52db63…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < 2a7c2f00843225d5f037676bca649321f3d024c7 (git) Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < a8820c8a7718327e96849782033e7c85a0f6bcfe (git) Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < 8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c (git) Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < 4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab (git) Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < d5d4a7b538b52db63927773a8905fcd9f78a42e2 (git)
Linux	Linux	Affected: 6.7 Unaffected: 0 , < 6.7 (semver) Unaffected: 6.12.108 , ≤ 6.12.* (semver) Unaffected: 6.18.49 , ≤ 6.18.* (semver) Unaffected: 7.1.13 , ≤ 7.1.* (semver) Unaffected: 7.2.3 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (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": "2a7c2f00843225d5f037676bca649321f3d024c7",
              "status": "affected",
              "version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
              "versionType": "git"
            },
            {
              "lessThan": "a8820c8a7718327e96849782033e7c85a0f6bcfe",
              "status": "affected",
              "version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
              "versionType": "git"
            },
            {
              "lessThan": "8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c",
              "status": "affected",
              "version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
              "versionType": "git"
            },
            {
              "lessThan": "4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab",
              "status": "affected",
              "version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
              "versionType": "git"
            },
            {
              "lessThan": "d5d4a7b538b52db63927773a8905fcd9f78a42e2",
              "status": "affected",
              "version": "c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f",
              "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": "6.7"
            },
            {
              "lessThan": "6.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.108",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.49",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.108",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.49",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.13",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.3",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: keep the last remote linked during FDB flush\n\nA non-nexthop FDB entry is expected to have at least one remote while it\nremains reachable through the FDB hash table. A filtered bulk flush\nviolates this invariant when every remote matches: It unlinks the last\nremote in vxlan_fdb_dst_destroy() and only afterwards tells vxlan_flush()\nto destroy the parent FDB entry.\n\nAn RCU reader can find the parent during this interval.\nfirst_remote_rcu() then applies list_entry_rcu() to the empty list head,\nproducing an invalid remote pointer that the receive learning path can\nread from and write to.\n\nWhen a matching remote is the sole remaining remote, leave it linked and\nask the caller to destroy the entire FDB entry. vxlan_fdb_destroy() keeps\nthe remote attached while sending the deletion notification and removing\nthe parent from the lookup structures."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-04T15:54:48.371Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/2a7c2f00843225d5f037676bca649321f3d024c7"
        },
        {
          "url": "https://git.kernel.org/stable/c/a8820c8a7718327e96849782033e7c85a0f6bcfe"
        },
        {
          "url": "https://git.kernel.org/stable/c/8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c"
        },
        {
          "url": "https://git.kernel.org/stable/c/4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab"
        },
        {
          "url": "https://git.kernel.org/stable/c/d5d4a7b538b52db63927773a8905fcd9f78a42e2"
        }
      ],
      "title": "vxlan: keep the last remote linked during FDB flush",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80838",
    "datePublished": "2026-09-04T15:54:48.371Z",
    "dateReserved": "2026-08-26T14:34:25.796Z",
    "dateUpdated": "2026-09-04T15:54:48.371Z",
    "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.

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