CVE-2018-7540

Status: ModifiedMedium (6.5)—
Severity6.5Medium · CVSS 3.0
Exploitation probability0.43 %higher than 36% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

An issue was discovered in Xen through 4.10.x allowing x86 PV guest OS users to cause a denial of service (host OS CPU hang) via non-preemptable L3/L4 pagetable freeing.

CVSS

Base score
6.5
Version
3.0
Vector
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.43 %
Percentile among all scored CVEs
36
Score date
10/20/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (2)

CWEs

References

Show 18 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2018-7540",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
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          "baseScore": 4.9,
          "accessVector": "LOCAL",
          "vectorString": "AV:L/AC:L/Au:N/C:N/I:N/A:C",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "LOW",
          "availabilityImpact": "COMPLETE",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 6.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 3.9,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV30": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "CHANGED",
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          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 4,
        "exploitabilityScore": 2
      }
    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2018-02-27T19:29:00.607",
  "references": [
    {
      "url": "http://www.securityfocus.com/bid/103174",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://www.securitytracker.com/id/1040773",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2018/03/msg00003.html",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2018/11/msg00013.html",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://security.gentoo.org/glsa/201810-06",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://support.citrix.com/article/CTX232096",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://support.citrix.com/article/CTX232655",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://www.debian.org/security/2018/dsa-4131",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://xenbits.xen.org/xsa/advisory-252.html",
      "tags": [
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      "source": "cve@mitre.org"
    },
    {
      "url": "http://www.securityfocus.com/bid/103174",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
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    {
      "url": "http://www.securitytracker.com/id/1040773",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2018/03/msg00003.html",
      "tags": [
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2018/11/msg00013.html",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://security.gentoo.org/glsa/201810-06",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://support.citrix.com/article/CTX232096",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://support.citrix.com/article/CTX232655",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://www.debian.org/security/2018/dsa-4131",
      "tags": [
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://xenbits.xen.org/xsa/advisory-252.html",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "An issue was discovered in Xen through 4.10.x allowing x86 PV guest OS users to cause a denial of service (host OS CPU hang) via non-preemptable L3/L4 pagetable freeing."
    },
    {
      "lang": "es",
      "value": "Se ha descubierto un problema en Xen hasta las versiones 4.10.x que permite que usuarios invitados del sistema operativo x86 PV provoquen una denegación de servicio (bloqueo de la CPU del sistema operativo del host) mediante la liberación de una página de tabla L3/L4 de tipo non-preemptable."
    }
  ],
  "lastModified": "2026-06-17T02:03:20.120",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "CCDFE96D-9999-441D-ACD6-74C3A2FDD8EF",
              "versionEndIncluding": "4.10.0"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve@mitre.org"
}