CVE-2025-58151 (GCVE-0-2025-58151)

Vulnerability from cvelistv5 – Published: 2026-07-09 14:45 – Updated: 2026-07-09 15:41
VLAI
Title
varstored: TOCTOU issues with mapped guest memory
Summary
varstored is a component of the Xapi toolstack handling UEFI Variables for a VM. It has a communication path with OVMF inside the VM involving mapping a buffer prepared by OVMF. Within varstored, there were insufficient compiler barriers, creating TOCTOU issues with data in the shared buffer. The exact vulnerable behaviour depends on the code generated by the compiler. In a build of varstored using default settings, the attacker can control an index used in a jump table.
Severity
9.4 (Critical)
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-09 15:40 UTC
CWE
  • CWE-367 - Time-of-check time-of-use (TOCTOU) race condition
Assigner
XEN CNA under the mitre root
CNA scorecard D 56/100 over 46 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Xen varstored Affected: all
guessed Create a notification for this product.
Date Public
2026-01-27 13:00
Credits
This issue was discovered by Teddy Astie of Vates.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-07-09T15:05:08.753Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/01/27/2"
          },
          {
            "url": "http://xenbits.xen.org/xsa/advisory-478.html"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2025-58151",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-09T15:40:36.292177Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-09T15:41:25.431Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "platforms": [
            "Linux"
          ],
          "product": "varstored",
          "vendor": "Xen",
          "versions": [
            {
              "status": "affected",
              "version": "all"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "This issue was discovered by Teddy Astie of Vates."
        }
      ],
      "datePublic": "2026-01-27T13:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cpre\u003evarstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table.\u003c/pre\u003e"
            }
          ],
          "value": "varstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-233",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-233 Privilege Escalation"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "LOCAL",
            "baseScore": 9.4,
            "baseSeverity": "CRITICAL",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "HIGH",
            "subConfidentialityImpact": "HIGH",
            "subIntegrityImpact": "HIGH",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-367",
              "description": "CWE-367 Time-of-check time-of-use (TOCTOU) race condition",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-09T14:45:16.531Z",
        "orgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
        "shortName": "XEN"
      },
      "references": [
        {
          "url": "https://xenbits.xen.org/xsa/advisory-478.html"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "varstored: TOCTOU issues with mapped guest memory",
      "x_generator": {
        "engine": "Vulnogram 1.0.2"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
    "assignerShortName": "XEN",
    "cveId": "CVE-2025-58151",
    "datePublished": "2026-07-09T14:45:16.531Z",
    "dateReserved": "2025-08-26T06:48:41.444Z",
    "dateUpdated": "2026-07-09T15:41:25.431Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-58151",
      "date": "2026-10-19",
      "epss": "0.00137",
      "percentile": "0.02813"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "platforms": [
                  "Linux"
                ],
                "product": "varstored",
                "vendor": "Xen",
                "versions": [
                  {
                    "status": "affected",
                    "version": "all"
                  }
                ]
              }
            ],
            "source": "security@xen.org"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "varstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table."
          },
          {
            "lang": "es",
            "value": "varstored es un componente de la pila de herramientas Xapi que gestiona las variables UEFI para una VM. Tiene una ruta de comunicaci\u00f3n con OVMF dentro de la VM que implica el mapeo de un b\u00fafer preparado por OVMF.\n\nDentro de varstored, hab\u00eda barreras de compilador insuficientes, creando problemas TOCTOU con los datos en el b\u00fafer compartido.\n\nEl comportamiento vulnerable exacto depende del c\u00f3digo generado por el compilador. En una compilaci\u00f3n de varstored utilizando la configuraci\u00f3n predeterminada, el atacante puede controlar un \u00edndice utilizado en una tabla de salto."
          }
        ],
        "id": "CVE-2025-58151",
        "lastModified": "2026-09-29T19:10:00.160",
        "metrics": {
          "cvssMetricV40": [
            {
              "cvssData": {
                "Automatable": "NOT_DEFINED",
                "Recovery": "NOT_DEFINED",
                "Safety": "NOT_DEFINED",
                "attackComplexity": "LOW",
                "attackRequirements": "NONE",
                "attackVector": "LOCAL",
                "availabilityRequirement": "NOT_DEFINED",
                "baseScore": 9.4,
                "baseSeverity": "CRITICAL",
                "confidentialityRequirement": "NOT_DEFINED",
                "exploitMaturity": "NOT_DEFINED",
                "integrityRequirement": "NOT_DEFINED",
                "modifiedAttackComplexity": "NOT_DEFINED",
                "modifiedAttackRequirements": "NOT_DEFINED",
                "modifiedAttackVector": "NOT_DEFINED",
                "modifiedPrivilegesRequired": "NOT_DEFINED",
                "modifiedSubAvailabilityImpact": "NOT_DEFINED",
                "modifiedSubConfidentialityImpact": "NOT_DEFINED",
                "modifiedSubIntegrityImpact": "NOT_DEFINED",
                "modifiedUserInteraction": "NOT_DEFINED",
                "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
                "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
                "modifiedVulnIntegrityImpact": "NOT_DEFINED",
                "privilegesRequired": "NONE",
                "providerUrgency": "NOT_DEFINED",
                "subAvailabilityImpact": "HIGH",
                "subConfidentialityImpact": "HIGH",
                "subIntegrityImpact": "HIGH",
                "userInteraction": "NONE",
                "valueDensity": "NOT_DEFINED",
                "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
                "version": "4.0",
                "vulnAvailabilityImpact": "HIGH",
                "vulnConfidentialityImpact": "HIGH",
                "vulnIntegrityImpact": "HIGH",
                "vulnerabilityResponseEffort": "NOT_DEFINED"
              },
              "source": "security@xen.org",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2025-58151",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-09T15:40:36.292177Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-07-09T16:16:33.817",
        "references": [
          {
            "source": "security@xen.org",
            "url": "https://xenbits.xen.org/xsa/advisory-478.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "http://www.openwall.com/lists/oss-security/2026/01/27/2"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "http://xenbits.xen.org/xsa/advisory-478.html"
          }
        ],
        "sourceIdentifier": "security@xen.org",
        "vulnStatus": "Deferred",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-367"
              }
            ],
            "source": "security@xen.org",
            "type": "Secondary"
          }
        ]
      }
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "providerMetadata": {
              "dateUpdated": "2026-07-09T15:05:08.753Z",
              "orgId": "af854a3a-2127-422b-91ae-364da2661108",
              "shortName": "CVE"
            },
            "references": [
              {
                "url": "http://www.openwall.com/lists/oss-security/2026/01/27/2"
              },
              {
                "url": "http://xenbits.xen.org/xsa/advisory-478.html"
              }
            ],
            "title": "CVE Program Container"
          },
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2025-58151",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "total"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-07-09T15:40:36.292177Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-07-09T15:41:20.901Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "defaultStatus": "unaffected",
              "platforms": [
                "Linux"
              ],
              "product": "varstored",
              "vendor": "Xen",
              "versions": [
                {
                  "status": "affected",
                  "version": "all"
                }
              ]
            }
          ],
          "credits": [
            {
              "lang": "en",
              "type": "finder",
              "value": "This issue was discovered by Teddy Astie of Vates."
            }
          ],
          "datePublic": "2026-01-27T13:00:00.000Z",
          "descriptions": [
            {
              "lang": "en",
              "supportingMedia": [
                {
                  "base64": false,
                  "type": "text/html",
                  "value": "\u003cpre\u003evarstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table.\u003c/pre\u003e"
                }
              ],
              "value": "varstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table."
            }
          ],
          "impacts": [
            {
              "capecId": "CAPEC-233",
              "descriptions": [
                {
                  "lang": "en",
                  "value": "CAPEC-233 Privilege Escalation"
                }
              ]
            }
          ],
          "metrics": [
            {
              "cvssV4_0": {
                "Automatable": "NOT_DEFINED",
                "Recovery": "NOT_DEFINED",
                "Safety": "NOT_DEFINED",
                "attackComplexity": "LOW",
                "attackRequirements": "NONE",
                "attackVector": "LOCAL",
                "baseScore": 9.4,
                "baseSeverity": "CRITICAL",
                "exploitMaturity": "NOT_DEFINED",
                "privilegesRequired": "NONE",
                "providerUrgency": "NOT_DEFINED",
                "subAvailabilityImpact": "HIGH",
                "subConfidentialityImpact": "HIGH",
                "subIntegrityImpact": "HIGH",
                "userInteraction": "NONE",
                "valueDensity": "NOT_DEFINED",
                "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
                "version": "4.0",
                "vulnAvailabilityImpact": "HIGH",
                "vulnConfidentialityImpact": "HIGH",
                "vulnIntegrityImpact": "HIGH",
                "vulnerabilityResponseEffort": "NOT_DEFINED"
              },
              "format": "CVSS",
              "scenarios": [
                {
                  "lang": "en",
                  "value": "GENERAL"
                }
              ]
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-367",
                  "description": "CWE-367 Time-of-check time-of-use (TOCTOU) race condition",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-07-09T14:45:16.531Z",
            "orgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
            "shortName": "XEN"
          },
          "references": [
            {
              "url": "https://xenbits.xen.org/xsa/advisory-478.html"
            }
          ],
          "source": {
            "discovery": "UNKNOWN"
          },
          "title": "varstored: TOCTOU issues with mapped guest memory",
          "x_generator": {
            "engine": "Vulnogram 1.0.2"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
        "assignerShortName": "XEN",
        "cveId": "CVE-2025-58151",
        "datePublished": "2026-07-09T14:45:16.531Z",
        "dateReserved": "2025-08-26T06:48:41.444Z",
        "dateUpdated": "2026-07-09T15:41:25.431Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.