Vulnerability-Lookup

GHSA-JX39-Q92M-WF39

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:31

Details

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

KVM: SEV: Ignore Port I/O requests of length '0'

Explicitly ignore Port I/O requests of length '0' (or count '0'), so that setting up the software scratch area (and other code) doesn't have to worry about underflowing the length, and to allow for WARNing on trying to configure the scratch area with len==0.

Severity

9.3 (Critical)


                  
                    CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-63940"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:12Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Ignore Port I/O requests of length \u00270\u0027\n\nExplicitly ignore Port I/O requests of length \u00270\u0027 (or count \u00270\u0027), so that\nsetting up the software scratch area (and other code) doesn\u0027t have to\nworry about underflowing the length, and to allow for WARNing on trying\nto configure the scratch area with len==0.",
  "id": "GHSA-jx39-q92m-wf39",
  "modified": "2026-07-20T15:31:52Z",
  "published": "2026-07-19T18:31:47Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63940"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2254972d4d69e279ba4e87bf0968eb08ad0d3c92"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3988bd2723de407ae90fa7a6f6029b4e60238c58"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3b6035bc6bff20e89752ce4358bc4c9a9d5883f2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c30cde934c7813b4e3069765dac64ce3d31e34f2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-63940 (GCVE-0-2026-63940)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:55 – Updated: 2026-07-20 13:41

Title

KVM: SEV: Ignore Port I/O requests of length '0'

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Ignore Port I/O requests of length '0' Explicitly ignore Port I/O requests of length '0' (or count '0'), so that setting up the software scratch area (and other code) doesn't have to worry about underflowing the length, and to allow for WARNing on trying to configure the scratch area with len==0.

Severity

9.3 (Critical)


                        
                          CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Assigner

Linux

References

4 references

URL	Tags
https://git.kernel.org/stable/c/3b6035bc6bff20e89…
https://git.kernel.org/stable/c/2254972d4d69e279b…
https://git.kernel.org/stable/c/c30cde934c7813b4e…
https://git.kernel.org/stable/c/3988bd2723de407ae…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 291bd20d5d88814a73d43b55b9428feab2f28094 , < 3b6035bc6bff20e89752ce4358bc4c9a9d5883f2 (git) Affected: 291bd20d5d88814a73d43b55b9428feab2f28094 , < 2254972d4d69e279ba4e87bf0968eb08ad0d3c92 (git) Affected: 291bd20d5d88814a73d43b55b9428feab2f28094 , < c30cde934c7813b4e3069765dac64ce3d31e34f2 (git) Affected: 291bd20d5d88814a73d43b55b9428feab2f28094 , < 3988bd2723de407ae90fa7a6f6029b4e60238c58 (git)
Linux	Linux	Affected: 5.11 Unaffected: 0 , < 5.11 (semver) Unaffected: 6.12.95 , ≤ 6.12.* (semver) Unaffected: 6.18.35 , ≤ 6.18.* (semver) Unaffected: 7.0.12 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/svm/sev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3b6035bc6bff20e89752ce4358bc4c9a9d5883f2",
              "status": "affected",
              "version": "291bd20d5d88814a73d43b55b9428feab2f28094",
              "versionType": "git"
            },
            {
              "lessThan": "2254972d4d69e279ba4e87bf0968eb08ad0d3c92",
              "status": "affected",
              "version": "291bd20d5d88814a73d43b55b9428feab2f28094",
              "versionType": "git"
            },
            {
              "lessThan": "c30cde934c7813b4e3069765dac64ce3d31e34f2",
              "status": "affected",
              "version": "291bd20d5d88814a73d43b55b9428feab2f28094",
              "versionType": "git"
            },
            {
              "lessThan": "3988bd2723de407ae90fa7a6f6029b4e60238c58",
              "status": "affected",
              "version": "291bd20d5d88814a73d43b55b9428feab2f28094",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/svm/sev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.11"
            },
            {
              "lessThan": "5.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.95",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.95",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.35",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.12",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Ignore Port I/O requests of length \u00270\u0027\n\nExplicitly ignore Port I/O requests of length \u00270\u0027 (or count \u00270\u0027), so that\nsetting up the software scratch area (and other code) doesn\u0027t have to\nworry about underflowing the length, and to allow for WARNing on trying\nto configure the scratch area with len==0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-20T13:41:42.039Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/3b6035bc6bff20e89752ce4358bc4c9a9d5883f2"
        },
        {
          "url": "https://git.kernel.org/stable/c/2254972d4d69e279ba4e87bf0968eb08ad0d3c92"
        },
        {
          "url": "https://git.kernel.org/stable/c/c30cde934c7813b4e3069765dac64ce3d31e34f2"
        },
        {
          "url": "https://git.kernel.org/stable/c/3988bd2723de407ae90fa7a6f6029b4e60238c58"
        }
      ],
      "title": "KVM: SEV: Ignore Port I/O requests of length \u00270\u0027",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63940",
    "datePublished": "2026-07-19T14:55:36.408Z",
    "dateReserved": "2026-07-19T07:54:57.022Z",
    "dateUpdated": "2026-07-20T13:41:42.039Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-JX39-Q92M-WF39

CVE-2026-63940 (GCVE-0-2026-63940)

Tags

Sightings

Nomenclature