Vulnerability-Lookup

FKIE_CVE-2026-45952

Vulnerability from fkie_nvd - Published: 2026-05-27 14:17 - Updated: 2026-05-27 14:48

Severity

Summary

In the Linux kernel, the following vulnerability has been resolved: eth: fbnic: Add validation for MTU changes Increasing the MTU beyond the HDS threshold causes the hardware to fragment packets across multiple buffers. If a single-buffer XDP program is attached, the driver will drop all multi-frag frames. While we can't prevent a remote sender from sending non-TCP packets larger than the MTU, this will prevent users from inadvertently breaking new TCP streams. Traditionally, drivers supported XDP with MTU less than 4Kb (packet per page). Fbnic currently prevents attaching XDP when MTU is too high. But it does not prevent increasing MTU after XDP is attached.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/03399063aa0c67fd8bdfd69467ddb849bb3b97df
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ccd8e87748ad083047d6c8544c5809b7f96cc8df
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/d7eaa006c0444a5d4671be7efe6dbb33ef8b515e

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\neth: fbnic: Add validation for MTU changes\n\nIncreasing the MTU beyond the HDS threshold causes the hardware to\nfragment packets across multiple buffers. If a single-buffer XDP program\nis attached, the driver will drop all multi-frag frames. While we can\u0027t\nprevent a remote sender from sending non-TCP packets larger than the MTU,\nthis will prevent users from inadvertently breaking new TCP streams.\n\nTraditionally, drivers supported XDP with MTU less than 4Kb\n(packet per page). Fbnic currently prevents attaching XDP when MTU is too high.\nBut it does not prevent increasing MTU after XDP is attached."
    }
  ],
  "id": "CVE-2026-45952",
  "lastModified": "2026-05-27T14:48:03.013",
  "metrics": {},
  "published": "2026-05-27T14:17:11.713",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/03399063aa0c67fd8bdfd69467ddb849bb3b97df"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ccd8e87748ad083047d6c8544c5809b7f96cc8df"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d7eaa006c0444a5d4671be7efe6dbb33ef8b515e"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}

CVE-2026-45952 (GCVE-0-2026-45952)

Vulnerability from cvelistv5 – Published: 2026-05-27 12:18 – Updated: 2026-05-27 12:18

Title

eth: fbnic: Add validation for MTU changes

Summary

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/d7eaa006c0444a5d4…
https://git.kernel.org/stable/c/03399063aa0c67fd8…
https://git.kernel.org/stable/c/ccd8e87748ad08304…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 1b0a3950dbd4fa278dc33401a4faba2a23307a16 , < d7eaa006c0444a5d4671be7efe6dbb33ef8b515e (git) Affected: 1b0a3950dbd4fa278dc33401a4faba2a23307a16 , < 03399063aa0c67fd8bdfd69467ddb849bb3b97df (git) Affected: 1b0a3950dbd4fa278dc33401a4faba2a23307a16 , < ccd8e87748ad083047d6c8544c5809b7f96cc8df (git)
Linux	Linux	Affected: 6.18 Unaffected: 0 , < 6.18 (semver) Unaffected: 6.18.14 , ≤ 6.18.* (semver) Unaffected: 6.19.4 , ≤ 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": [
            "drivers/net/ethernet/meta/fbnic/fbnic_netdev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "d7eaa006c0444a5d4671be7efe6dbb33ef8b515e",
              "status": "affected",
              "version": "1b0a3950dbd4fa278dc33401a4faba2a23307a16",
              "versionType": "git"
            },
            {
              "lessThan": "03399063aa0c67fd8bdfd69467ddb849bb3b97df",
              "status": "affected",
              "version": "1b0a3950dbd4fa278dc33401a4faba2a23307a16",
              "versionType": "git"
            },
            {
              "lessThan": "ccd8e87748ad083047d6c8544c5809b7f96cc8df",
              "status": "affected",
              "version": "1b0a3950dbd4fa278dc33401a4faba2a23307a16",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/meta/fbnic/fbnic_netdev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.18"
            },
            {
              "lessThan": "6.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.14",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.4",
              "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": "6.18.14",
                  "versionStartIncluding": "6.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.4",
                  "versionStartIncluding": "6.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "6.18",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\neth: fbnic: Add validation for MTU changes\n\nIncreasing the MTU beyond the HDS threshold causes the hardware to\nfragment packets across multiple buffers. If a single-buffer XDP program\nis attached, the driver will drop all multi-frag frames. While we can\u0027t\nprevent a remote sender from sending non-TCP packets larger than the MTU,\nthis will prevent users from inadvertently breaking new TCP streams.\n\nTraditionally, drivers supported XDP with MTU less than 4Kb\n(packet per page). Fbnic currently prevents attaching XDP when MTU is too high.\nBut it does not prevent increasing MTU after XDP is attached."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-27T12:18:08.442Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/d7eaa006c0444a5d4671be7efe6dbb33ef8b515e"
        },
        {
          "url": "https://git.kernel.org/stable/c/03399063aa0c67fd8bdfd69467ddb849bb3b97df"
        },
        {
          "url": "https://git.kernel.org/stable/c/ccd8e87748ad083047d6c8544c5809b7f96cc8df"
        }
      ],
      "title": "eth: fbnic: Add validation for MTU changes",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-45952",
    "datePublished": "2026-05-27T12:18:08.442Z",
    "dateReserved": "2026-05-13T15:03:33.088Z",
    "dateUpdated": "2026-05-27T12:18:08.442Z",
    "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.

Action not permitted

FKIE_CVE-2026-45952

CVE-2026-45952 (GCVE-0-2026-45952)

Tags

Sightings

Nomenclature