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CVE-2026-89725

Estado: RecibidaAlta (8.8)—

In the Linux kernel, the following vulnerability has been resolved:

media: cec: stm32: prevent out-of-bounds write on RX overflow

stm32_rx_done() appends each received CEC byte to rx_msg.msg[] using rx_msg.len as the write index, incrementing it on every RXBR (receive-byte-ready) interrupt without checking it against the buffer size:

rx_msg.msg[] is a fixed CEC_MAX_MSG_SIZE (16) byte array in struct cec_msg, and rx_msg.len is only reset on RXACKE/RXOVR or after a completed message (RXEND).

Leer descripción completaMostrar menos

The number of bytes received before RXEND is decided by the remote CEC device (it sets EOM), not by the driver. A peer that keeps sending bytes without ending the message drives RXBR repeatedly, pushing rx_msg.len past 16 and writing peer-controlled bytes out of bounds into the surrounding memory. This is reachable in normal operation once the driver has probed and receiving is enabled, from the IRQ thread, without any local privilege.

The length check in the CEC core runs on the consumer side, after the byte has been stored, so it does not prevent the overflow. Bound the index in the driver before the store, as the other platform CEC drivers already do (e.g. tegra_cec), dropping the excess bytes of an overlong frame.

Found by static analysis tool CodeQL.

Detalles técnicos trazas, registros y código del informe original
	cec->rx_msg.msg[cec->rx_msg.len++] = val & 0xFF;

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

AV:A (red adyacente) sin privilegios ni interacción del usuario → T1210. Escritura fuera de límites en memoria desde un peer CEC remoto puede escalar privilegios (kernel) o causar DoS. Explotable sin privilegios locales desde IRQ.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-89725",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.8,
          "attackVector": "ADJACENT_NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 2.8
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "d69ae57453c80a2193bcdb3fd762efbec447eecf",
              "lessThan": "f2499b720ea9b874d58770885c6c2e8445a8c3ef",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d69ae57453c80a2193bcdb3fd762efbec447eecf",
              "lessThan": "3df1a4026662121011187247897fe95fd84e8a3a",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d69ae57453c80a2193bcdb3fd762efbec447eecf",
              "lessThan": "37ac45f7d6e3a6a5dcf6452a0b7bad9a543e8344",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d69ae57453c80a2193bcdb3fd762efbec447eecf",
              "lessThan": "1b4fdefd788db990d1805feb5c7b2388de791ecd",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d69ae57453c80a2193bcdb3fd762efbec447eecf",
              "lessThan": "c3edd7fb8e3692423a702705509947fc9c30b3d1",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d69ae57453c80a2193bcdb3fd762efbec447eecf",
              "lessThan": "0c260d3f97e52978a8c769bb095ac0901333a3ac",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d69ae57453c80a2193bcdb3fd762efbec447eecf",
              "lessThan": "a85ce3b175615c2e13bc01e8a1b6b6b6910fde57",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d69ae57453c80a2193bcdb3fd762efbec447eecf",
              "lessThan": "fb9dda38d4b9e90db07ed9a0ee2d35bf85494035",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/media/cec/platform/stm32/stm32-cec.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.13"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "4.13",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.10.270",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.221",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.109",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/media/cec/platform/stm32/stm32-cec.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-11T20:20:02.567",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0c260d3f97e52978a8c769bb095ac0901333a3ac",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/1b4fdefd788db990d1805feb5c7b2388de791ecd",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/37ac45f7d6e3a6a5dcf6452a0b7bad9a543e8344",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3df1a4026662121011187247897fe95fd84e8a3a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a85ce3b175615c2e13bc01e8a1b6b6b6910fde57",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c3edd7fb8e3692423a702705509947fc9c30b3d1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f2499b720ea9b874d58770885c6c2e8445a8c3ef",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/fb9dda38d4b9e90db07ed9a0ee2d35bf85494035",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: cec: stm32: prevent out-of-bounds write on RX overflow\n\nstm32_rx_done() appends each received CEC byte to rx_msg.msg[] using\nrx_msg.len as the write index, incrementing it on every RXBR\n(receive-byte-ready) interrupt without checking it against the buffer\nsize:\n\n\tcec->rx_msg.msg[cec->rx_msg.len++] = val & 0xFF;\n\nrx_msg.msg[] is a fixed CEC_MAX_MSG_SIZE (16) byte array in struct\ncec_msg, and rx_msg.len is only reset on RXACKE/RXOVR or after a\ncompleted message (RXEND). The number of bytes received before RXEND is\ndecided by the remote CEC device (it sets EOM), not by the driver. A\npeer that keeps sending bytes without ending the message drives RXBR\nrepeatedly, pushing rx_msg.len past 16 and writing peer-controlled bytes\nout of bounds into the surrounding memory. This is reachable in normal\noperation once the driver has probed and receiving is enabled, from the\nIRQ thread, without any local privilege.\n\nThe length check in the CEC core runs on the consumer side, after the\nbyte has been stored, so it does not prevent the overflow. Bound the\nindex in the driver before the store, as the other platform CEC drivers\nalready do (e.g. tegra_cec), dropping the excess bytes of an overlong\nframe.\n\nFound by static analysis tool CodeQL."
    }
  ],
  "lastModified": "2026-09-14T13:19:21.730",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}