{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "0a19e61e6d4c6192077ead760ba0a2d350987d4c"
            },
            {
              "fixed": "0282fb1c4b638eecfe2cc558092c460911d8f7e2"
            },
            {
              "fixed": "907adc667d902fafbdb2d740d57b55bd025dc4cd"
            },
            {
              "fixed": "f20be33d093ce7630c17ff7ed93caf7eaf8ac1a3"
            },
            {
              "fixed": "af3f80ca4c8b17f20f9e588def076288fdb49e65"
            },
            {
              "fixed": "499a8a66b1598bfab97182aed15e0f1646074a3d"
            },
            {
              "fixed": "4c2e1d359d7a2b82cdf3254e4e480af9417f99fb"
            },
            {
              "fixed": "d5d096cd9369e986d4e5153baa86b8b35c283e09"
            },
            {
              "fixed": "a005b7f1a491ffda61bff0fd0f6548f8986fb977"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.12.0"
            },
            {
              "fixed": "5.10.266"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.217"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.184"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.153"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.105"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.46"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80550.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio_ccw: Fix out of bounds check on CCW array\n\nThe routine ccwchain_calc_length() counts the number of channel\ncommand words (CCWs) that are chained together in a single channel\nprogram, and rejects anything larger than CCWCHAIN_LEN_MAX (256) CCWs.\n\nThe loop itself is \"do..while (count \u003c 257)\", and while the logic in\nis_cpa_within_range() correctly adjusts between the 0-index array of\nCCWs and the count of CCWs starting at 1, this means it would look\nat a possible 257th CCW before ending the loop and (correctly)\nreturning an error.\n\nFix this by restructuring the loop to break as soon as 256 CCWs\n(thus indexes 0-255) are examined, without looking at memory\noutside the range.",
  "id": "CVE-2026-80550",
  "modified": "2026-08-28T03:30:23.978281153Z",
  "published": "2026-08-26T14:37:19.956Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0282fb1c4b638eecfe2cc558092c460911d8f7e2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/499a8a66b1598bfab97182aed15e0f1646074a3d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4c2e1d359d7a2b82cdf3254e4e480af9417f99fb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/907adc667d902fafbdb2d740d57b55bd025dc4cd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a005b7f1a491ffda61bff0fd0f6548f8986fb977"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/af3f80ca4c8b17f20f9e588def076288fdb49e65"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d5d096cd9369e986d4e5153baa86b8b35c283e09"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f20be33d093ce7630c17ff7ed93caf7eaf8ac1a3"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80550.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80550"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "s390/vfio_ccw: Fix out of bounds check on CCW array"
}