CVE-2026-80554

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: s390/vfio_ccw: Limit the number of channel program segments The processing of channel programs, and the CCWs within them, is done recursively. As such, there is an arbitrary (but not architectural) limit to the number of CCWs that can exist in a single channel program. The vfio-ccw logic breaks these channel programs into segments whenever it encounters a Transfer-In-Channel (TIC) CCW, and the combined number of segments count towards the global limit. Impose an equivalent limit to the number of segments until such logic can be made non-recursive.

Severity

CRITICAL

CVSS score

9.3 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-08-26 15:17:09.990000

Last modified

2026-10-30 13:20:06.877000

View original CVE JSON

{
  "id": "CVE-2026-80554",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-26T15:17:09.990",
  "lastModified": "2026-10-30T13:20:06.877",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio_ccw: Limit the number of channel program segments\n\nThe processing of channel programs, and the CCWs within them, is done\nrecursively. As such, there is an arbitrary (but not architectural)\nlimit to the number of CCWs that can exist in a single channel program.\n\nThe vfio-ccw logic breaks these channel programs into segments whenever\nit encounters a Transfer-In-Channel (TIC) CCW, and the combined number\nof segments count towards the global limit. Impose an equivalent limit\nto the number of segments until such logic can be made non-recursive."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/s390/cio/vfio_ccw_cp.c",
            "drivers/s390/cio/vfio_ccw_cp.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
              "lessThan": "2ce00bb19db13606cda79f4b7aae4d9775de3096",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
              "lessThan": "15fb4559a7fdf0b8725e433a71cfd03a1313a48b",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
              "lessThan": "a1625f66eaa1200068a0e2c05bc90e65182fc4e3",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
              "lessThan": "06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
              "lessThan": "4ee94790490ae8dcc97df8597f07836c8a81bbcf",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "0a19e61e6d4c6192077ead760ba0a2d350987d4c",
              "lessThan": "5405c90d6a47b3014e74ee0618a162449abbbc93",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/s390/cio/vfio_ccw_cp.c",
            "drivers/s390/cio/vfio_ccw_cp.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.12",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.12",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.153",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.105",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.46",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.10",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
          "baseScore": 9.3,
          "baseSeverity": "CRITICAL",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "CHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.5,
        "impactScore": 6.0
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T19:17:23.132592Z",
          "id": "CVE-2026-80554",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/15fb4559a7fdf0b8725e433a71cfd03a1313a48b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2ce00bb19db13606cda79f4b7aae4d9775de3096",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4ee94790490ae8dcc97df8597f07836c8a81bbcf",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5405c90d6a47b3014e74ee0618a162449abbbc93",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a1625f66eaa1200068a0e2c05bc90e65182fc4e3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}