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CVE-2026-64524

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: drm/hyperv: validate resolution_count and fix WIN8 fallback A SYNTHVID_RESOLUTION_RESPONSE with resolution_count > 64 walks past the supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT] array in the parse loop. Bound resolution_count against the array size, folded into the existing zero-check. When the WIN10 resolution probe fails, the caller in hyperv_connect_vsp() left hv->screen_*_max / preferred_* unpopulated, which sets mode_config.max_width / max_height to 0 and makes drm_internal_framebuffer_create() reject every userspace framebuffer with -EINVAL. The pre-WIN10 branch had the same gap for preferred_width / preferred_height. Use a single post-probe fallback guarded by screen_width_max == 0 so both paths converge on the WIN8 defaults.

Severity
HIGH
CVSS score
7.7 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-25 10:17:38.713000
Last modified
2026-10-19 21:17:41.977000
View original CVE JSON 
{
  "id": "CVE-2026-64524",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-07-25T10:17:38.713",
  "lastModified": "2026-10-19T21:17:41.977",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/hyperv: validate resolution_count and fix WIN8 fallback\n\nA SYNTHVID_RESOLUTION_RESPONSE with resolution_count > 64 walks past\nthe supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT] array in the\nparse loop. Bound resolution_count against the array size, folded\ninto the existing zero-check.\n\nWhen the WIN10 resolution probe fails, the caller in\nhyperv_connect_vsp() left hv->screen_*_max / preferred_* unpopulated,\nwhich sets mode_config.max_width / max_height to 0 and makes\ndrm_internal_framebuffer_create() reject every userspace framebuffer\nwith -EINVAL. The pre-WIN10 branch had the same gap for\npreferred_width / preferred_height. Use a single post-probe fallback\nguarded by screen_width_max == 0 so both paths converge on the WIN8\ndefaults."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/gpu/drm/hyperv/hyperv_drm_proto.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0",
              "lessThan": "96f7de3172d4aa878b7f87173b2b3507c350fcd6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0",
              "lessThan": "bc573752f3dac0d1ab8df7078c1851bc76717653",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0",
              "lessThan": "1fb565b77b8f44afabb02de6310065f109d89e94",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0",
              "lessThan": "a321c908f2eeea01539668eb270d074d9b88e490",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0",
              "lessThan": "9c698b2c43c2667c34f5336bf46ad5786216ac2a",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0",
              "lessThan": "8a114b25b5521eae451b13bce98ae978624962e5",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "76c56a5affeba1e163b66b9d8cc192e6154466f0",
              "lessThan": "13d33b9ef67066c77c84273fac5a1d3fde3533d1",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/gpu/drm/hyperv/hyperv_drm_proto.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.14",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.14",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.210",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.176",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.143",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.93",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.35",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.0.12",
              "lessThanOrEqual": "7.0.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1",
              "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:U/C:H/I:N/A:H",
          "baseScore": 7.7,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.5,
        "impactScore": 5.2
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T15:41:39.558295Z",
          "id": "CVE-2026-64524",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-122"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/13d33b9ef67066c77c84273fac5a1d3fde3533d1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/1fb565b77b8f44afabb02de6310065f109d89e94",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8a114b25b5521eae451b13bce98ae978624962e5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/96f7de3172d4aa878b7f87173b2b3507c350fcd6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9c698b2c43c2667c34f5336bf46ad5786216ac2a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a321c908f2eeea01539668eb270d074d9b88e490",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/bc573752f3dac0d1ab8df7078c1851bc76717653",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}