CVE-2026-127928 (GCVE-0-2026-127928)

Vulnerability from cvelistv5 – Published: 2026-11-13 00:22 – Updated: 2026-11-13 00:22
VLAI
Title
AES image key left on the stack after serial-recovery encrypted-image handling in MCUboot
Summary
In MCUboot's serial-recovery encrypted-image support (boot/boot_serial/src/boot_serial_encryption.c), decrypt_image_inplace() and boot_image_validate_encrypted() each keep a stack-local struct boot_status. boot_enc_load() writes the plaintext per-image AES key into its enckey[] field. Neither function cleared this structure before returning. In addition, a decrypt failure inside the per-sector loop of decrypt_image_inplace() returned early and skipped the total_out: cleanup, which left the expanded AES key context (enc_data) on the stack as well. The error paths of boot_image_validate_encrypted() similarly skipped boot_enc_zeroize(). The affected code is built when encrypted images (MCUBOOT_ENC_IMAGES, Zephyr CONFIG_BOOT_ENCRYPT_IMAGE) are combined with serial recovery. It runs when an encrypted image is uploaded to the primary slot over the recovery protocol, and when the image list or state is queried while an encrypted image is in the secondary slot. After these functions return, the image's AES content key remains in dead stack memory. An attacker who can later read device RAM, for example through a debug port or retained RAM, can recover it. This weakens the confidentiality of image-encryption keys within the bootloader trust boundary. A recovered key exposes the plaintext of the encrypted firmware image it protects. The device's long-term private decryption key is not exposed. No remote or recovery-protocol channel that returns this memory is known, so exploitation requires a separate memory-read capability.
Severity
2 (Low)
CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
CWE
Assigner
zephyr CNA under the mitre root
CNA scorecard B 77/100 over 237 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
mcu-tools mcuboot Affected: 1.9.0 , < 2.5.0 (semver)
guessed Create a notification for this product.
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{
  "containers": {
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          "defaultStatus": "unaffected",
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          "programFiles": [
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            "boot/zephyr/single_loader.c"
          ],
          "programRoutines": [
            {
              "name": "boot_image_validate_encrypted"
            },
            {
              "name": "decrypt_image_inplace"
            }
          ],
          "vendor": "mcu-tools",
          "versions": [
            {
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              "status": "affected",
              "version": "1.9.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In MCUboot\u0027s serial-recovery encrypted-image support (boot/boot_serial/src/boot_serial_encryption.c), decrypt_image_inplace() and boot_image_validate_encrypted() each keep a stack-local struct boot_status. boot_enc_load() writes the plaintext per-image AES key into its enckey[] field. Neither function cleared this structure before returning. In addition, a decrypt failure inside the per-sector loop of decrypt_image_inplace() returned early and skipped the total_out: cleanup, which left the expanded AES key context (enc_data) on the stack as well. The error paths of boot_image_validate_encrypted() similarly skipped boot_enc_zeroize().\n\nThe affected code is built when encrypted images (MCUBOOT_ENC_IMAGES, Zephyr CONFIG_BOOT_ENCRYPT_IMAGE) are combined with serial recovery. It runs when an encrypted image is uploaded to the primary slot over the recovery protocol, and when the image list or state is queried while an encrypted image is in the secondary slot. After these functions return, the image\u0027s AES content key remains in dead stack memory. An attacker who can later read device RAM, for example through a debug port or retained RAM, can recover it.\n\nThis weakens the confidentiality of image-encryption keys within the bootloader trust boundary. A recovered key exposes the plaintext of the encrypted firmware image it protects. The device\u0027s long-term private decryption key is not exposed. No remote or recovery-protocol channel that returns this memory is known, so exploitation requires a separate memory-read capability."
        }
      ],
      "metrics": [
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            "baseScore": 2,
            "baseSeverity": "LOW",
            "vectorString": "CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
          },
          "format": "CVSS"
        }
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      "problemTypes": [
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          "descriptions": [
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              "description": "info-leak",
              "lang": "en",
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            }
          ]
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-13T00:22:56.789Z",
        "orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
        "shortName": "zephyr"
      },
      "references": [
        {
          "name": "Fix commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/mcu-tools/mcuboot/commit/411949f830724617fbc08b9b32f0a45ba0c80baf"
        },
        {
          "name": "GHSA-hqmg-jwp9-8cf8",
          "url": "https://github.com/mcu-tools/mcuboot/security/advisories/GHSA-hqmg-jwp9-8cf8"
        }
      ],
      "title": "AES image key left on the stack after serial-recovery encrypted-image handling in MCUboot",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
    "assignerShortName": "zephyr",
    "cveId": "CVE-2026-127928",
    "datePublished": "2026-11-13T00:22:56.789Z",
    "dateReserved": "2026-11-12T19:48:25.870Z",
    "dateUpdated": "2026-11-13T00:22:56.789Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "affected": [
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                "defaultStatus": "unaffected",
                "packageName": "mcuboot",
                "product": "mcuboot",
                "programFiles": [
                  "boot/boot_serial/src/boot_serial_encryption.c",
                  "boot/zephyr/single_loader.c"
                ],
                "programRoutines": [
                  {
                    "name": "boot_image_validate_encrypted"
                  },
                  {
                    "name": "decrypt_image_inplace"
                  }
                ],
                "vendor": "mcu-tools",
                "versions": [
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                    "status": "affected",
                    "version": "1.9.0",
                    "versionType": "semver"
                  }
                ]
              }
            ],
            "source": "vulnerabilities@zephyrproject.org"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In MCUboot\u0027s serial-recovery encrypted-image support (boot/boot_serial/src/boot_serial_encryption.c), decrypt_image_inplace() and boot_image_validate_encrypted() each keep a stack-local struct boot_status. boot_enc_load() writes the plaintext per-image AES key into its enckey[] field. Neither function cleared this structure before returning. In addition, a decrypt failure inside the per-sector loop of decrypt_image_inplace() returned early and skipped the total_out: cleanup, which left the expanded AES key context (enc_data) on the stack as well. The error paths of boot_image_validate_encrypted() similarly skipped boot_enc_zeroize().\n\nThe affected code is built when encrypted images (MCUBOOT_ENC_IMAGES, Zephyr CONFIG_BOOT_ENCRYPT_IMAGE) are combined with serial recovery. It runs when an encrypted image is uploaded to the primary slot over the recovery protocol, and when the image list or state is queried while an encrypted image is in the secondary slot. After these functions return, the image\u0027s AES content key remains in dead stack memory. An attacker who can later read device RAM, for example through a debug port or retained RAM, can recover it.\n\nThis weakens the confidentiality of image-encryption keys within the bootloader trust boundary. A recovered key exposes the plaintext of the encrypted firmware image it protects. The device\u0027s long-term private decryption key is not exposed. No remote or recovery-protocol channel that returns this memory is known, so exploitation requires a separate memory-read capability."
          }
        ],
        "id": "CVE-2026-127928",
        "lastModified": "2026-11-13T02:18:56.133",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "PHYSICAL",
                "availabilityImpact": "NONE",
                "baseScore": 2.0,
                "baseSeverity": "LOW",
                "confidentialityImpact": "LOW",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 0.5,
              "impactScore": 1.4,
              "source": "vulnerabilities@zephyrproject.org",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-11-13T02:18:56.133",
        "references": [
          {
            "source": "vulnerabilities@zephyrproject.org",
            "url": "https://github.com/mcu-tools/mcuboot/commit/411949f830724617fbc08b9b32f0a45ba0c80baf"
          },
          {
            "source": "vulnerabilities@zephyrproject.org",
            "url": "https://github.com/mcu-tools/mcuboot/security/advisories/GHSA-hqmg-jwp9-8cf8"
          }
        ],
        "sourceIdentifier": "vulnerabilities@zephyrproject.org",
        "vulnStatus": "Received",
        "weaknesses": [
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            "description": [
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                "lang": "en",
                "value": "CWE-226"
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            ],
            "source": "vulnerabilities@zephyrproject.org",
            "type": "Secondary"
          }
        ]
      }
    }
  }
}



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