Vulnerability-Lookup

FKIE_CVE-2026-89448

Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-14 13:19

Severity

9.3 (Critical) - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Force requesting ACS when tboot is enabled Currently the conditions of requesting ACS in detect_intel_iommu() don't include tboot, leading to a possible misconfiguration with ACS disabled (e.g. due to user opts) while iommu is later forced on by tboot_force_iommu(). Fix it by checking tboot in detect_intel_iommu().

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/45705a6bfdb283f7b3b509010fd617b72f942537
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/579eb867d3da63f3b5e32f235925e1daa7ec70d0
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/607432b2618b61df81134be0ef2562b8300c1216
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/87bc611c6c98a41c00feb7b06b0c297dd141a2ae
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/aaeb81241e802c86be69394f72d49fde3f861fbb

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/intel/dmar.c",
            "drivers/iommu/intel/iommu.c",
            "drivers/iommu/intel/iommu.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "579eb867d3da63f3b5e32f235925e1daa7ec70d0",
              "status": "affected",
              "version": "5d990b627537e59a3a2f039ff588a4750e9c1a6a",
              "versionType": "git"
            },
            {
              "lessThan": "aaeb81241e802c86be69394f72d49fde3f861fbb",
              "status": "affected",
              "version": "5d990b627537e59a3a2f039ff588a4750e9c1a6a",
              "versionType": "git"
            },
            {
              "lessThan": "45705a6bfdb283f7b3b509010fd617b72f942537",
              "status": "affected",
              "version": "5d990b627537e59a3a2f039ff588a4750e9c1a6a",
              "versionType": "git"
            },
            {
              "lessThan": "87bc611c6c98a41c00feb7b06b0c297dd141a2ae",
              "status": "affected",
              "version": "5d990b627537e59a3a2f039ff588a4750e9c1a6a",
              "versionType": "git"
            },
            {
              "lessThan": "607432b2618b61df81134be0ef2562b8300c1216",
              "status": "affected",
              "version": "5d990b627537e59a3a2f039ff588a4750e9c1a6a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/intel/dmar.c",
            "drivers/iommu/intel/iommu.c",
            "drivers/iommu/intel/iommu.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.33"
            },
            {
              "lessThan": "2.6.33",
              "status": "unaffected",
              "version": "0",
              "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"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Force requesting ACS when tboot is enabled\n\nCurrently the conditions of requesting ACS in detect_intel_iommu()\ndon\u0027t include tboot, leading to a possible misconfiguration with ACS\ndisabled (e.g. due to user opts) while iommu is later forced on by\ntboot_force_iommu().\n\nFix it by checking tboot in detect_intel_iommu()."
    }
  ],
  "id": "CVE-2026-89448",
  "lastModified": "2026-09-14T13:19:01.800",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 9.3,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.5,
        "impactScore": 6.0,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-11T20:19:25.347",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/45705a6bfdb283f7b3b509010fd617b72f942537"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/579eb867d3da63f3b5e32f235925e1daa7ec70d0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/607432b2618b61df81134be0ef2562b8300c1216"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/87bc611c6c98a41c00feb7b06b0c297dd141a2ae"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/aaeb81241e802c86be69394f72d49fde3f861fbb"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-89448 (GCVE-0-2026-89448)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:43 – Updated: 2026-09-14 11:59

Title

iommu/vt-d: Force requesting ACS when tboot is enabled

Summary

Severity

9.3 (Critical)


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

Assigner

Linux mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/579eb867d3da63f3b…
https://git.kernel.org/stable/c/aaeb81241e802c86b…
https://git.kernel.org/stable/c/45705a6bfdb283f7b…
https://git.kernel.org/stable/c/87bc611c6c98a41c0…
https://git.kernel.org/stable/c/607432b2618b61df8…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 5d990b627537e59a3a2f039ff588a4750e9c1a6a , < 579eb867d3da63f3b5e32f235925e1daa7ec70d0 (git) Affected: 5d990b627537e59a3a2f039ff588a4750e9c1a6a , < aaeb81241e802c86be69394f72d49fde3f861fbb (git) Affected: 5d990b627537e59a3a2f039ff588a4750e9c1a6a , < 45705a6bfdb283f7b3b509010fd617b72f942537 (git) Affected: 5d990b627537e59a3a2f039ff588a4750e9c1a6a , < 87bc611c6c98a41c00feb7b06b0c297dd141a2ae (git) Affected: 5d990b627537e59a3a2f039ff588a4750e9c1a6a , < 607432b2618b61df81134be0ef2562b8300c1216 (git)
Linux	Linux	Affected: 2.6.33 Unaffected: 0 , < 2.6.33 (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/iommu/intel/dmar.c",
            "drivers/iommu/intel/iommu.c",
            "drivers/iommu/intel/iommu.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "579eb867d3da63f3b5e32f235925e1daa7ec70d0",
              "status": "affected",
              "version": "5d990b627537e59a3a2f039ff588a4750e9c1a6a",
              "versionType": "git"
            },
            {
              "lessThan": "aaeb81241e802c86be69394f72d49fde3f861fbb",
              "status": "affected",
              "version": "5d990b627537e59a3a2f039ff588a4750e9c1a6a",
              "versionType": "git"
            },
            {
              "lessThan": "45705a6bfdb283f7b3b509010fd617b72f942537",
              "status": "affected",
              "version": "5d990b627537e59a3a2f039ff588a4750e9c1a6a",
              "versionType": "git"
            },
            {
              "lessThan": "87bc611c6c98a41c00feb7b06b0c297dd141a2ae",
              "status": "affected",
              "version": "5d990b627537e59a3a2f039ff588a4750e9c1a6a",
              "versionType": "git"
            },
            {
              "lessThan": "607432b2618b61df81134be0ef2562b8300c1216",
              "status": "affected",
              "version": "5d990b627537e59a3a2f039ff588a4750e9c1a6a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/iommu/intel/dmar.c",
            "drivers/iommu/intel/iommu.c",
            "drivers/iommu/intel/iommu.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.33"
            },
            {
              "lessThan": "2.6.33",
              "status": "unaffected",
              "version": "0",
              "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": "6.6.157",
                  "versionStartIncluding": "2.6.33",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.109",
                  "versionStartIncluding": "2.6.33",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "2.6.33",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "2.6.33",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "2.6.33",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Force requesting ACS when tboot is enabled\n\nCurrently the conditions of requesting ACS in detect_intel_iommu()\ndon\u0027t include tboot, leading to a possible misconfiguration with ACS\ndisabled (e.g. due to user opts) while iommu is later forced on by\ntboot_force_iommu().\n\nFix it by checking tboot in detect_intel_iommu()."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - detect_intel_iommu() runs at boot from pci_iommu_alloc() and, when tboot later forces VT-d on, skips pci_request_acs(); a local PCIe/Thunderbolt DMA device or VFIO-passthrough guest can then spoof requester IDs and issue peer-to-peer DMA. This is not a network-protocol path.\nAC:L - On a tboot launch where intel_iommu=off, iommu=off, or default dmar_disabled skipped pci_request_acs(), ACS SV/RR/CR/UF/TB are never programmed; an attacker-controlled device can then deterministically perform P2P DMA or RID spoofing with no race or layout luck.\nPR:N - A malicious PCIe/Thunderbolt device or a tenant with an assigned passthrough/SR-IOV function issues the DMA itself and needs no host account, capability, or init-namespace root, matching other VT-d isolation-bypass scores for unauthenticated devices.\nUI:N - After the kernel boots with tboot-forced VT-d and ACS still disabled, the attacker\u2019s device performs DMA on its own; no separate victim action such as mounting a filesystem or opening a file is required.\nS:C - Missing ACS lets a device spoof requester IDs and send peer-to-peer TLPs that never reach the IOMMU, crossing the device/host DMA isolation boundary that tboot forces VT-d on to enforce (IOMMU/DMA boundary bypass is Scope Changed).\nC:H - Without ACS source validation, request redirect, and translation blocking, a device can impersonate another requester ID or DMA to peer BARs, reading host or peer-device memory outside its IOMMU domain (arbitrary DMA disclosure).\nI:H - The same ACS gap yields DMA writes into host or peer-device memory, including ATS without translation blocking on external/untrusted ports, providing an arbitrary write primitive that can corrupt kernel memory and hijack control flow.\nA:H - Unchecked DMA writes and IOMMU-bypassing P2P traffic can corrupt kernel structures or provoke DMAR faults, oopses, and panics; any such host crash qualifies as High availability impact."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-14T11:59:55.683Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/579eb867d3da63f3b5e32f235925e1daa7ec70d0"
        },
        {
          "url": "https://git.kernel.org/stable/c/aaeb81241e802c86be69394f72d49fde3f861fbb"
        },
        {
          "url": "https://git.kernel.org/stable/c/45705a6bfdb283f7b3b509010fd617b72f942537"
        },
        {
          "url": "https://git.kernel.org/stable/c/87bc611c6c98a41c00feb7b06b0c297dd141a2ae"
        },
        {
          "url": "https://git.kernel.org/stable/c/607432b2618b61df81134be0ef2562b8300c1216"
        }
      ],
      "title": "iommu/vt-d: Force requesting ACS when tboot is enabled",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89448",
    "datePublished": "2026-09-11T19:43:14.746Z",
    "dateReserved": "2026-09-11T19:38:34.706Z",
    "dateUpdated": "2026-09-14T11:59:55.683Z",
    "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.

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FKIE_CVE-2026-89448

CVE-2026-89448 (GCVE-0-2026-89448)

Tags

Sightings

Nomenclature