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CVE-2026-89481

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: fix host memory disclosure on R2T for a read command nvme_tcp_handle_r2t() does not check the direction of the request the R2T refers to. A malicious controller can send an R2T for a READ and the host will answer it: nvme_tcp_setup_h2c_data_pdu() builds the H2CData header and nvme_tcp_try_send_data() sends the request's data buffer. That buffer is the READ destination, so its contents go to the controller. The command then completes normally and nothing is logged. Against a test controller that answers every READ with an R2T, a 4096 byte buffered read returned all 4096 bytes, split over two R2Ts. The pages contained stale kernel data, including an array of struct page pointers. Reject an R2T for a request that is not a write.

Severity
HIGH
CVSS score
7.5 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-11 20:19:29.600000
Last modified
2026-10-30 13:20:17.727000
View original CVE JSON
{
  "id": "CVE-2026-89481",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-11T20:19:29.600",
  "lastModified": "2026-10-30T13:20:17.727",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvme-tcp: fix host memory disclosure on R2T for a read command\n\nnvme_tcp_handle_r2t() does not check the direction of the request the\nR2T refers to. A malicious controller can send an R2T for a READ and\nthe host will answer it: nvme_tcp_setup_h2c_data_pdu() builds the\nH2CData header and nvme_tcp_try_send_data() sends the request's data\nbuffer. That buffer is the READ destination, so its contents go to the\ncontroller.\n\nThe command then completes normally and nothing is logged.\n\nAgainst a test controller that answers every READ with an R2T, a 4096\nbyte buffered read returned all 4096 bytes, split over two R2Ts. The\npages contained stale kernel data, including an array of struct page\npointers.\n\nReject an R2T for a request that is not a write."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/nvme/host/tcp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "lessThan": "effe898669c5f69ed519d6339be01ee9cd91d1a4",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "lessThan": "377aa04d7b3e73ffef6364818def188da8d6f025",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "lessThan": "49a4dcf57608ebf6432dbcb203ed25e7ed581445",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "lessThan": "bc4013c7cce58d46f792c8c87bc8c8318a70190e",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "lessThan": "a4c3c7310156493797c920b10d8648c07aa05403",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "lessThan": "3b3d27670c0c890ba7cf1bc3614cab61bde6d25c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "lessThan": "3a0b05145053a5fad1a2ddb4e4d87b07385e63e5",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "lessThan": "6efbc52237facda35d2d874fe1765bb4839275d8",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/nvme/host/tcp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.0",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.0",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.273",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.224",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.188",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.157",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.109",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.50",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.4",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "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:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T19:22:35.614121Z",
          "id": "CVE-2026-89481",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/377aa04d7b3e73ffef6364818def188da8d6f025",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3a0b05145053a5fad1a2ddb4e4d87b07385e63e5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3b3d27670c0c890ba7cf1bc3614cab61bde6d25c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/49a4dcf57608ebf6432dbcb203ed25e7ed581445",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6efbc52237facda35d2d874fe1765bb4839275d8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a4c3c7310156493797c920b10d8648c07aa05403",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/bc4013c7cce58d46f792c8c87bc8c8318a70190e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
      "url": "https://git.kernel.org/stable/c/effe898669c5f69ed519d6339be01ee9cd91d1a4",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}