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CVE-2026-72345 (GCVE-0-2026-72345)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:55 – Updated: 2026-08-17 05:43
VLAI
Title
net/mlx5: LAG, Fix off-by-one in single-FDB error rollback
Summary
In the Linux kernel, the following vulnerability has been resolved: net/mlx5: LAG, Fix off-by-one in single-FDB error rollback On failure at index i, the reverse cleanup loop in mlx5_lag_create_single_fdb() starts from i, so the failed index itself is rolled back. That can operate on uninitialized state or double-tear-down a rule the add_one path already self-rolled-back. Start the rollback from i - 1 so only successfully-installed entries are undone.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: ddbb5ddc43ad000a984149db5af1133433938404 , < 40cc06bf71476932e5d139fa326dcd0372766e16 (git)
Affected: ddbb5ddc43ad000a984149db5af1133433938404 , < 0f0e4ae6975c773f7854fc48932a267f6c79088f (git)
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Linux Linux Affected: 6.14
Unaffected: 0 , < 6.14 (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ethernet/mellanox/mlx5/core/lag/shared_fdb.c"
          ],
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          "vendor": "Linux",
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              "lessThan": "40cc06bf71476932e5d139fa326dcd0372766e16",
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              "versionType": "git"
            },
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          "vendor": "Linux",
          "versions": [
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              "version": "6.14"
            },
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
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              "versionType": "semver"
            },
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              "status": "unaffected",
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        }
      ],
      "cpeApplicability": [
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                  "versionStartIncluding": "6.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.14",
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              "negate": false,
              "operator": "OR"
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      "descriptions": [
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          "lang": "en",
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        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The bug is only reachable when mlx5 shared-FDB LAG setup runs via local admin paths (bond netdev notifier or devlink esw_multiport), not from remote packet handling on the mlx5 data path.\nAC:L - An attacker with CAP_NET_ADMIN can trigger bonding/MPESW setup and retry until mlx5_eswitch_offloads_single_fdb_add_one fails, reliably exercising the faulty rollback loop without uncontrollable timing or layout dependencies.\nPR:L - Exploitation requires configuring bonding or devlink eswitch parameters, which needs CAP_NET_ADMIN; per kernel CNA guidance this is Low because that capability is obtainable inside unprivileged user namespaces.\nUI:N - No end-user interaction is required beyond the attacker (or their privileged account) performing the LAG/shared-FDB configuration that reaches mlx5_lag_create_single_fdb().\nS:U - Impact is confined to kernel mlx5 eswitch/LAG state on the host; it does not cross a VM, container, or IOMMU security boundary into another authority.\nC:H - The off-by-one rollback can tear down uninitialized or already-cleared eswitch flow/FDB state, causing memory corruption that can be leveraged for kernel information disclosure beyond a simple crash.\nI:H - Double teardown of master egress bounce rules and slave root FDB entries can corrupt mlx5 steering structures and heap metadata, enabling arbitrary kernel writes or control-flow hijacking.\nA:H - Incorrect rollback of failed single-FDB installs can panic the kernel or leave eswitch offload state inconsistent, causing oops, hang, or denial of service on affected Mellanox hosts."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:43:04.347Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/40cc06bf71476932e5d139fa326dcd0372766e16"
        },
        {
          "url": "https://git.kernel.org/stable/c/0f0e4ae6975c773f7854fc48932a267f6c79088f"
        }
      ],
      "title": "net/mlx5: LAG, Fix off-by-one in single-FDB error rollback",
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  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72345",
    "datePublished": "2026-08-15T05:55:50.427Z",
    "dateReserved": "2026-08-09T03:40:39.920Z",
    "dateUpdated": "2026-08-17T05:43:04.347Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-72345",
      "date": "2026-09-05",
      "epss": "0.00165",
      "percentile": "0.06028"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-72345\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-15T06:22:07.870\",\"lastModified\":\"2026-08-17T06:18:38.440\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nnet/mlx5: LAG, Fix off-by-one in single-FDB error rollback\\n\\nOn failure at index i, the reverse cleanup loop in\\nmlx5_lag_create_single_fdb() starts from i, so the failed index\\nitself is rolled back. That can operate on uninitialized state or\\ndouble-tear-down a rule the add_one path already self-rolled-back.\\n\\nStart the rollback from i - 1 so only successfully-installed entries\\nare undone.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/net/ethernet/mellanox/mlx5/core/lag/shared_fdb.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"ddbb5ddc43ad000a984149db5af1133433938404\",\"lessThan\":\"40cc06bf71476932e5d139fa326dcd0372766e16\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ddbb5ddc43ad000a984149db5af1133433938404\",\"lessThan\":\"0f0e4ae6975c773f7854fc48932a267f6c79088f\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/net/ethernet/mellanox/mlx5/core/lag/shared_fdb.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.14\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.14\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.5\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0f0e4ae6975c773f7854fc48932a267f6c79088f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/40cc06bf71476932e5d139fa326dcd0372766e16\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-19T17:39:37+00:00",
      "cve": "CVE-2026-72345",
      "id": "CVE-2026-72345",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_affected": "198",
      "product_status:known_not_affected": "76",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: net/mlx5: LAG, Fix off-by-one in single-FDB error rollback",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72345.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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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.
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  • 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.


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