Numeric truncation in the MPU buffer authorization check in FreeRTOS-Kernel

{
  "id": "c06a6fd254b7d2f6a80a29e853f9e0044d29383fc7829d8f653b255f6e5e25fe",
  "url": "https://osv.dev/vulnerability/CVE-2026-109588",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Numeric truncation in the MPU buffer authorization check in FreeRTOS-Kernel",
    "summary": "Numeric truncation of the buffer length in the MPU buffer authorization check in FreeRTOS-Kernel V11.3.0 and V11.3.1 on the Arm Cortex-R82 (Armv8-R AArch64) MPU port might allow, under certain conditions, an unprivileged task on MPU-enabled builds to read or write privileged kernel memory beyond the validated buffer window, via a stream buffer system call. To remediate this issue, users should upgrade to version V11.3.2 or later.",
    "evidence": "osv:CVE-2026-109588",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-109588",
      "aliases": [
        "CVE-2026-109588",
        "GHSA-qf4j-6f5j-876g"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/freertos/freertos-kernel",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "8a59a4b19bf72977819feddef87d41163ced7004"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "fixed": "8a59a4b19bf72977819feddef87d41163ced7004"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "V11.3.2"
                  }
                ]
              }
            }
          ],
          "versions": [
            "V10.4.3",
            "V10.4.2",
            "V10.4.1-kernel-only",
            "V10.4.0-kernel-only",
            "V10.3.1-kernel-only",
            "V10.3.0-kernel-only"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-109588.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:36.918466601Z",
      "provider": "osv",
      "references": [
        "https://aws.amazon.com/security/security-bulletins/2026-138-aws/",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/109xxx/CVE-2026-109588.json",
        "https://github.com/FreeRTOS/FreeRTOS-Kernel/security/advisories/GHSA-qf4j-6f5j-876g",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-109588",
        "https://github.com/FreeRTOS/FreeRTOS-Kernel/releases/tag/V11.3.2"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-125",
          "CWE-197",
          "CWE-787"
        ],
        "cna_assigner": "AMZN",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "11.3.0"
                  },
                  {
                    "last_affected": "11.3.1"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          },
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "11.3.0"
                  },
                  {
                    "last_affected": "11.3.1"
                  }
                ],
                "source": "CPE_FIELD",
                "strategy": "CPEApplicability"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/109xxx/CVE-2026-109588.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-109588",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 504375,
  "published_at": "2026-10-16T17:09:51.788+00:00"
}