Vulnerability-Lookup

GHSA-FMG2-X8FR-FW62

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-14 15:32

Details

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

7.5 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-89481"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:19:29Z",
    "severity": "HIGH"
  },
  "details": "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\u0027s 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.",
  "id": "GHSA-fmg2-x8fr-fw62",
  "modified": "2026-09-14T15:32:25Z",
  "published": "2026-09-11T21:31:28Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89481"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3a0b05145053a5fad1a2ddb4e4d87b07385e63e5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3b3d27670c0c890ba7cf1bc3614cab61bde6d25c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/49a4dcf57608ebf6432dbcb203ed25e7ed581445"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6efbc52237facda35d2d874fe1765bb4839275d8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a4c3c7310156493797c920b10d8648c07aa05403"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bc4013c7cce58d46f792c8c87bc8c8318a70190e"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-89481 (GCVE-0-2026-89481)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:43 – Updated: 2026-09-14 12:00

Title

nvme-tcp: fix host memory disclosure on R2T for a read command

Summary

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

7.5 (High)


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

Assigner

Linux mitre root

References

6 references

URL	Tags
https://git.kernel.org/stable/c/49a4dcf57608ebf64…
https://git.kernel.org/stable/c/bc4013c7cce58d46f…
https://git.kernel.org/stable/c/a4c3c731015649379…
https://git.kernel.org/stable/c/3b3d27670c0c890ba…
https://git.kernel.org/stable/c/3a0b05145053a5fad…
https://git.kernel.org/stable/c/6efbc52237facda35…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 3f2304f8c6d6ed97849057bd16fee99e434ca796 , < 49a4dcf57608ebf6432dbcb203ed25e7ed581445 (git) Affected: 3f2304f8c6d6ed97849057bd16fee99e434ca796 , < bc4013c7cce58d46f792c8c87bc8c8318a70190e (git) Affected: 3f2304f8c6d6ed97849057bd16fee99e434ca796 , < a4c3c7310156493797c920b10d8648c07aa05403 (git) Affected: 3f2304f8c6d6ed97849057bd16fee99e434ca796 , < 3b3d27670c0c890ba7cf1bc3614cab61bde6d25c (git) Affected: 3f2304f8c6d6ed97849057bd16fee99e434ca796 , < 3a0b05145053a5fad1a2ddb4e4d87b07385e63e5 (git) Affected: 3f2304f8c6d6ed97849057bd16fee99e434ca796 , < 6efbc52237facda35d2d874fe1765bb4839275d8 (git)
Linux	Linux	Affected: 5.0 Unaffected: 0 , < 5.0 (semver) Unaffected: 6.1.188 , ≤ 6.1.* (semver) Unaffected: 6.6.157 , ≤ 6.6.* (semver) Unaffected: 6.12.109 , ≤ 6.12.* (semver) Unaffected: 6.18.50 , ≤ 6.18.* (semver) Unaffected: 7.2.4 , ≤ 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/nvme/host/tcp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "49a4dcf57608ebf6432dbcb203ed25e7ed581445",
              "status": "affected",
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "versionType": "git"
            },
            {
              "lessThan": "bc4013c7cce58d46f792c8c87bc8c8318a70190e",
              "status": "affected",
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "versionType": "git"
            },
            {
              "lessThan": "a4c3c7310156493797c920b10d8648c07aa05403",
              "status": "affected",
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "versionType": "git"
            },
            {
              "lessThan": "3b3d27670c0c890ba7cf1bc3614cab61bde6d25c",
              "status": "affected",
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "versionType": "git"
            },
            {
              "lessThan": "3a0b05145053a5fad1a2ddb4e4d87b07385e63e5",
              "status": "affected",
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "versionType": "git"
            },
            {
              "lessThan": "6efbc52237facda35d2d874fe1765bb4839275d8",
              "status": "affected",
              "version": "3f2304f8c6d6ed97849057bd16fee99e434ca796",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/nvme/host/tcp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.0"
            },
            {
              "lessThan": "5.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.109",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "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": "6.1.188",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.157",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.109",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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\u0027s 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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The bug is in the NVMe-over-TCP host PDU receive path (nvme_tcp_recv_skb \u2192 nvme_tcp_handle_r2t). A remote NVMe-oF target or on-path attacker sends an R2T PDU over TCP (port 4420) and the host splices the READ destination buffer back over that socket.\nAC:L - A malicious controller that replies to an in-flight READ with a well-formed R2T always triggers the leak; the reporter reproduced a full 4096-byte disclosure with a test target. No race, special memory layout, or rare config beyond CONFIG_NVME_TCP is required.\nPR:N - NVMe/TCP requires no authentication by default (TLS and DH-HMAC-CHAP are optional and off in stock configs), so the remote peer needs no privileges or credentials on the victim host; it simply answers I/O the host is already sending.\nUI:N - No victim action is required at exploit time; once the host is connected (including via nvmf-autoconnect at boot), ordinary filesystem or block I/O issues READ commands and the malicious target triggers the leak by replying with R2T PDUs.\nS:U - The disclosure is of the host kernel\u0027s own I/O buffers and page-cache pages to the connected target. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - nvme_tcp_try_send_data() splices the READ destination pages to the attacker. Those pages hold stale kernel memory (reproduced: 4096 bytes including struct page pointers). Every subsequent READ can leak another MDTS-sized buffer of recycled kernel pages.\nI:N - The host only transmits existing buffer contents; the bug does not write attacker-controlled data into kernel memory, corrupt kernel structures, or provide a write or control-flow hijack primitive.\nA:N - The malformed R2T path completes the command successfully with nothing logged; the reporter observed a silent disclosure with no oops, panic, hang, or other availability impact."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-14T12:00:18.149Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/49a4dcf57608ebf6432dbcb203ed25e7ed581445"
        },
        {
          "url": "https://git.kernel.org/stable/c/bc4013c7cce58d46f792c8c87bc8c8318a70190e"
        },
        {
          "url": "https://git.kernel.org/stable/c/a4c3c7310156493797c920b10d8648c07aa05403"
        },
        {
          "url": "https://git.kernel.org/stable/c/3b3d27670c0c890ba7cf1bc3614cab61bde6d25c"
        },
        {
          "url": "https://git.kernel.org/stable/c/3a0b05145053a5fad1a2ddb4e4d87b07385e63e5"
        },
        {
          "url": "https://git.kernel.org/stable/c/6efbc52237facda35d2d874fe1765bb4839275d8"
        }
      ],
      "title": "nvme-tcp: fix host memory disclosure on R2T for a read command",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89481",
    "datePublished": "2026-09-11T19:43:36.589Z",
    "dateReserved": "2026-09-11T19:38:34.711Z",
    "dateUpdated": "2026-09-14T12:00:18.149Z",
    "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.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.