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CVE-2026-68278

Estado: RecibidaSin puntuar—

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

drm/dp/mst: fix buffer overflows in sideband chunk accumulation

drm_dp_sideband_append_payload() has three related bugs when processing device-provided sideband reply data:

All three are reachable from any DP MST device that can forge sideband reply messages on a physical connection.

Detalles técnicos trazas, registros y código del informe original
1. Zero-length curchunk_len underflow: msg_len is a 6-bit field taken
   directly from the DP sideband header. If a device sends msg_len=0,
   curchunk_len is set to zero. The condition (curchunk_idx >= curchunk_len)
   is immediately true, and curchunk_len-1 wraps to 255 (u8 underflow).
   drm_dp_msg_data_crc4() reads 255 bytes from chunk[48], then memcpy()
   writes 255 bytes into msg[], both far out of bounds.

2. chunk[48] overflow: curchunk_len can reach 63 (6-bit field). chunk[] is
   only 48 bytes. Multi-iteration payload assembly appends 16-byte blocks
   until curchunk_idx reaches curchunk_len, writing up to 15 bytes past
   the end of chunk[] into msg[].

3. msg[256] overflow: each chunk contributes (curchunk_len-1) bytes to
   msg[]. No check ensures curlen + (curchunk_len-1) stays within msg[256],
   so the memcpy can spill into adjacent struct fields.

CVSS

NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).

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).

Tecnologías afectadas (1)

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

Linux — Linux KernelAI

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-68278",
  "cveTags": [],
  "metrics": {},
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
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              "version": "ad7f8a1f9ced7f049f9b66d588723f243a7034cd",
              "lessThan": "ef2ecb6cf268debf3890df99fea01b6452dcf78e",
              "versionType": "git"
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            {
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              "versionType": "git"
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            {
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              "versionType": "git"
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        },
        {
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            },
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              "version": "0",
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            },
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              "status": "unaffected",
              "version": "5.10.266",
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            },
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              "version": "5.15.217",
              "versionType": "semver",
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            },
            {
              "status": "unaffected",
              "version": "6.1.183",
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            },
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              "status": "unaffected",
              "version": "6.6.148",
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            },
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              "version": "6.12.101",
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            },
            {
              "status": "unaffected",
              "version": "6.18.42",
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            },
            {
              "status": "unaffected",
              "version": "7.1.6",
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            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/gpu/drm/display/drm_dp_mst_topology.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-10T13:20:16.920",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1e5827839ad0ceb0079d1560c321fa3656b54f21",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
      "url": "https://git.kernel.org/stable/c/55bd5e685bda455b9b50c835f8c8442d52a344a3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
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    {
      "url": "https://git.kernel.org/stable/c/d4e05dedb252ed3e540a0c9be511e427f098110a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ef0dbcc200c3389f1f781ab181932a97e54b51af",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ef2ecb6cf268debf3890df99fea01b6452dcf78e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/dp/mst: fix buffer overflows in sideband chunk accumulation\n\ndrm_dp_sideband_append_payload() has three related bugs when processing\ndevice-provided sideband reply data:\n\n1. Zero-length curchunk_len underflow: msg_len is a 6-bit field taken\n   directly from the DP sideband header. If a device sends msg_len=0,\n   curchunk_len is set to zero. The condition (curchunk_idx >= curchunk_len)\n   is immediately true, and curchunk_len-1 wraps to 255 (u8 underflow).\n   drm_dp_msg_data_crc4() reads 255 bytes from chunk[48], then memcpy()\n   writes 255 bytes into msg[], both far out of bounds.\n\n2. chunk[48] overflow: curchunk_len can reach 63 (6-bit field). chunk[] is\n   only 48 bytes. Multi-iteration payload assembly appends 16-byte blocks\n   until curchunk_idx reaches curchunk_len, writing up to 15 bytes past\n   the end of chunk[] into msg[].\n\n3. msg[256] overflow: each chunk contributes (curchunk_len-1) bytes to\n   msg[]. No check ensures curlen + (curchunk_len-1) stays within msg[256],\n   so the memcpy can spill into adjacent struct fields.\n\nAll three are reachable from any DP MST device that can forge sideband\nreply messages on a physical connection."
    }
  ],
  "lastModified": "2026-08-23T13:16:36.020",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}