Vulnerability-Lookup

FKIE_CVE-2025-40266

Vulnerability from fkie_nvd - Published: 2025-12-04 16:16 - Updated: 2026-10-18 16:10

Severity

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

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Check the untrusted offset in FF-A memory share Verify the offset to prevent OOB access in the hypervisor FF-A buffer in case an untrusted large enough value [U32_MAX - sizeof(struct ffa_composite_mem_region) + 1, U32_MAX] is set from the host kernel.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/103e17aac09cdd358133f9e00998b75d6c1f1518
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/bc1909ef38788f2ee3d8011d70bf029948433051
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/f9f1aed6c8a3427900da3121e1868124854569c3
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/fc3139d9f4c1fe1c7d5f25f99676bd8e9c6a1041

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/kvm/hyp/nvhe/ffa.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "fc3139d9f4c1fe1c7d5f25f99676bd8e9c6a1041",
              "status": "affected",
              "version": "6211753fdfd05af9e08f54c8d0ba3ee516034878",
              "versionType": "git"
            },
            {
              "lessThan": "bc1909ef38788f2ee3d8011d70bf029948433051",
              "status": "affected",
              "version": "6211753fdfd05af9e08f54c8d0ba3ee516034878",
              "versionType": "git"
            },
            {
              "lessThan": "f9f1aed6c8a3427900da3121e1868124854569c3",
              "status": "affected",
              "version": "6211753fdfd05af9e08f54c8d0ba3ee516034878",
              "versionType": "git"
            },
            {
              "lessThan": "103e17aac09cdd358133f9e00998b75d6c1f1518",
              "status": "affected",
              "version": "6211753fdfd05af9e08f54c8d0ba3ee516034878",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/kvm/hyp/nvhe/ffa.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.11"
            },
            {
              "lessThan": "3.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.118",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.60",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "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\nKVM: arm64: Check the untrusted offset in FF-A memory share\n\nVerify the offset to prevent OOB access in the hypervisor\nFF-A buffer in case an untrusted large enough value\n[U32_MAX - sizeof(struct ffa_composite_mem_region) + 1, U32_MAX]\nis set from the host kernel."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nKVM: arm64: Verificar el desplazamiento no confiable en la compartici\u00f3n de memoria FF-A\n\nVerificar el desplazamiento para prevenir el acceso OOB en el b\u00fafer FF-A del hipervisor en caso de que un valor no confiable lo suficientemente grande\n[U32_MAX - sizeof(struct ffa_composite_mem_region) + 1, U32_MAX]\nsea establecido desde el kernel anfitri\u00f3n."
    }
  ],
  "id": "CVE-2025-40266",
  "lastModified": "2026-10-18T16:10:00.100",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 8.2,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "HIGH",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.5,
        "impactScore": 6.0,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2025-40266",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-06-16T19:59:35.285244Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2025-12-04T16:16:20.787",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/103e17aac09cdd358133f9e00998b75d6c1f1518"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bc1909ef38788f2ee3d8011d70bf029948433051"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f9f1aed6c8a3427900da3121e1868124854569c3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fc3139d9f4c1fe1c7d5f25f99676bd8e9c6a1041"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Deferred"
}

CVE-2025-40266 (GCVE-0-2025-40266)

Vulnerability from cvelistv5 – Published: 2025-12-04 16:08 – Updated: 2026-08-05 12:09

Title

KVM: arm64: Check the untrusted offset in FF-A memory share

Summary

Severity

8.2 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-16 19:59 UTC

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 7018 records in the last 180 days details

References

4 references

URL	Tags
https://git.kernel.org/stable/c/fc3139d9f4c1fe1c7…
https://git.kernel.org/stable/c/bc1909ef38788f2ee…
https://git.kernel.org/stable/c/f9f1aed6c8a342790…
https://git.kernel.org/stable/c/103e17aac09cdd358…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 6211753fdfd05af9e08f54c8d0ba3ee516034878 , < fc3139d9f4c1fe1c7d5f25f99676bd8e9c6a1041 (git) Affected: 6211753fdfd05af9e08f54c8d0ba3ee516034878 , < bc1909ef38788f2ee3d8011d70bf029948433051 (git) Affected: 6211753fdfd05af9e08f54c8d0ba3ee516034878 , < f9f1aed6c8a3427900da3121e1868124854569c3 (git) Affected: 6211753fdfd05af9e08f54c8d0ba3ee516034878 , < 103e17aac09cdd358133f9e00998b75d6c1f1518 (git)
Linux	Linux	Affected: 3.11 Unaffected: 0 , < 3.11 (semver) Unaffected: 6.6.118 , ≤ 6.6.* (semver) Unaffected: 6.12.60 , ≤ 6.12.* (semver) Unaffected: 6.17.10 , ≤ 6.17.* (semver) Unaffected: 6.18 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2025-40266",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-16T19:59:35.285244Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-16T19:59:44.078Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/kvm/hyp/nvhe/ffa.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "fc3139d9f4c1fe1c7d5f25f99676bd8e9c6a1041",
              "status": "affected",
              "version": "6211753fdfd05af9e08f54c8d0ba3ee516034878",
              "versionType": "git"
            },
            {
              "lessThan": "bc1909ef38788f2ee3d8011d70bf029948433051",
              "status": "affected",
              "version": "6211753fdfd05af9e08f54c8d0ba3ee516034878",
              "versionType": "git"
            },
            {
              "lessThan": "f9f1aed6c8a3427900da3121e1868124854569c3",
              "status": "affected",
              "version": "6211753fdfd05af9e08f54c8d0ba3ee516034878",
              "versionType": "git"
            },
            {
              "lessThan": "103e17aac09cdd358133f9e00998b75d6c1f1518",
              "status": "affected",
              "version": "6211753fdfd05af9e08f54c8d0ba3ee516034878",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/kvm/hyp/nvhe/ffa.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.11"
            },
            {
              "lessThan": "3.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.118",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.60",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.118",
                  "versionStartIncluding": "3.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.60",
                  "versionStartIncluding": "3.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17.10",
                  "versionStartIncluding": "3.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18",
                  "versionStartIncluding": "3.11",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Check the untrusted offset in FF-A memory share\n\nVerify the offset to prevent OOB access in the hypervisor\nFF-A buffer in case an untrusted large enough value\n[U32_MAX - sizeof(struct ffa_composite_mem_region) + 1, U32_MAX]\nis set from the host kernel."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The vulnerable code is the EL2 FF-A proxy, reached only via an SMC trapped from host EL1 with a host-supplied TX mailbox; this requires local execution on the machine, with no network or physical vector.\nAC:L - The host kernel fully controls the SMC registers (len/fraglen) and every byte of the TX buffer including composite_off, so the condition is set deterministically with no race or memory-layout dependency.\nPR:H - SMC is undefined at EL0 and no userspace FF-A interface exists, so the attacker must already execute code in the host kernel at EL1 \u2014 real root plus kernel-level access, not reachable through user namespaces.\nUI:N - The attacker issues the FFA_MEM_SHARE/FFA_MEM_LEND SMC itself; no victim action or interaction of any kind is needed.\nS:C - The vulnerable component is the pKVM EL2 hypervisor, a distinct security authority whose purpose is isolating protected guest VMs and the secure world from the untrusted host; corrupting it impacts resources beyond the host kernel\u0027s own authority.\nC:H - The out-of-bounds read extends far past the single-page hyp TX buffer with attacker-chosen displacement and unbounded length, and the OOB contents drive observable host-page sharing decisions, forming a disclosure oracle over hypervisor-private memory.\nI:H - Out-of-bounds constituent data is passed to __pkvm_host_share_ffa(), corrupting the hypervisor\u0027s page-ownership state and defeating the FF-A filter that prevents host-mediated exposure of protected guest memory to the secure world.\nA:H - Walking hundreds of millions of constituents past a one-page EL2 mapping faults in the hypervisor, causing hyp_panic and taking down the host and every guest on the system."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:09:01.305Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/fc3139d9f4c1fe1c7d5f25f99676bd8e9c6a1041"
        },
        {
          "url": "https://git.kernel.org/stable/c/bc1909ef38788f2ee3d8011d70bf029948433051"
        },
        {
          "url": "https://git.kernel.org/stable/c/f9f1aed6c8a3427900da3121e1868124854569c3"
        },
        {
          "url": "https://git.kernel.org/stable/c/103e17aac09cdd358133f9e00998b75d6c1f1518"
        }
      ],
      "title": "KVM: arm64: Check the untrusted offset in FF-A memory share",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-40266",
    "datePublished": "2025-12-04T16:08:25.392Z",
    "dateReserved": "2025-04-16T07:20:57.183Z",
    "dateUpdated": "2026-08-05T12:09:01.305Z",
    "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.

Vulnerability timeline

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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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