{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "ad7f8a1f9ced7f049f9b66d588723f243a7034cd"
            },
            {
              "fixed": "53937a2787d29c7a460e984dc4f20ff6ac91dc65"
            },
            {
              "fixed": "ef0dbcc200c3389f1f781ab181932a97e54b51af"
            },
            {
              "fixed": "1e5827839ad0ceb0079d1560c321fa3656b54f21"
            },
            {
              "fixed": "a6366b551079c79bf7bdbadd74c97358bcfe2d58"
            },
            {
              "fixed": "55bd5e685bda455b9b50c835f8c8442d52a344a3"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.17.0"
            },
            {
              "fixed": "6.6.148"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.101"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.42"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68278.json"
  },
  "details": "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 \u003e= 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.",
  "id": "CVE-2026-68278",
  "modified": "2026-08-12T03:51:12.376040893Z",
  "published": "2026-08-10T12:01:54.285Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1e5827839ad0ceb0079d1560c321fa3656b54f21"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/53937a2787d29c7a460e984dc4f20ff6ac91dc65"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/55bd5e685bda455b9b50c835f8c8442d52a344a3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a6366b551079c79bf7bdbadd74c97358bcfe2d58"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ef0dbcc200c3389f1f781ab181932a97e54b51af"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68278.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68278"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "drm/dp/mst: fix buffer overflows in sideband chunk accumulation"
}