Vulnerability-Lookup

GHSA-3FJR-PMVP-G6Q5

Vulnerability from github – Published: 2025-12-04 18:30 – Updated: 2026-07-30 06:32

Details

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.

Severity

8.2 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2025-40266"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-12-04T16:16:20Z",
    "severity": "HIGH"
  },
  "details": "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.",
  "id": "GHSA-3fjr-pmvp-g6q5",
  "modified": "2026-07-30T06:32:18Z",
  "published": "2025-12-04T18:30:53Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40266"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/103e17aac09cdd358133f9e00998b75d6c1f1518"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bc1909ef38788f2ee3d8011d70bf029948433051"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f9f1aed6c8a3427900da3121e1868124854569c3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fc3139d9f4c1fe1c7d5f25f99676bd8e9c6a1041"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

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

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.

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)

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            "other": {
              "content": {
                "id": "CVE-2025-40266",
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                "role": "CISA Coordinator",
                "timestamp": "2026-06-16T19:59:35.285244Z",
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          "shortName": "CISA-ADP"
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        "title": "CISA ADP Vulnrichment"
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.118",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.60",
              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "6.17.10",
              "versionType": "semver"
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              "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."
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    "state": "PUBLISHED"
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  "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.

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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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