MOKSHA-2026-0016

Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
Title
PVinPVH Xen Kernel Command-Line Injection via VM.platform
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can inject arbitrary Xen hypervisor boot parameters into the PVinPVH xen-shim kernel command line by setting VM.platform:pvinpvh-xen-cmdline to an attacker-controlled string. xenopsd reads this value with zero validation and passes it directly to xenguesthelper. The attacker can disable speculative execution mitigations (spec-ctrl=no), remove Meltdown protection (xpti=false), disable L1TF mitigation (pv-l1tf=false), and disable DMA protection (iommu=no) for the affected PVinPVH domain.
Severity
7.6 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H
8.5 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H
CWE
  • CWE-862 - Missing Authorization
  • CWE-20 - Improper Input Validation
References
Impacted products
Credits
Jakob Wolffhechel, Moksha
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "XenServer",
          "vendor": "Cloud Software Group",
          "versions": [
            {
              "status": "affected",
              "version": "all",
              "versionType": "custom"
            }
          ]
        },
        {
          "product": "XCP-ng",
          "vendor": "Vates",
          "versions": [
            {
              "status": "affected",
              "version": "all",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Jakob Wolffhechel, Moksha"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can inject arbitrary Xen hypervisor boot parameters into the PVinPVH xen-shim kernel command line by setting VM.platform:pvinpvh-xen-cmdline to an attacker-controlled string. xenopsd reads this value with zero validation and passes it directly to xenguesthelper. The attacker can disable speculative execution mitigations (spec-ctrl=no), remove Meltdown protection (xpti=false), disable L1TF mitigation (pv-l1tf=false), and disable DMA protection (iommu=no) for the affected PVinPVH domain."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.6,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H",
            "version": "3.1"
          },
          "format": "CVSS"
        },
        {
          "cvssV4_0": {
            "baseScore": 8.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H",
            "version": "4.0"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-862",
              "description": "Missing Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "Improper Input Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-24T06:00:00Z",
        "orgId": "moksha.dk",
        "shortName": "Moksha"
      },
      "references": [
        {
          "url": "https://cna.moksha.dk/MOKSHA-2026-0016"
        }
      ],
      "title": "PVinPVH Xen Kernel Command-Line Injection via VM.platform"
    }
  },
  "cveMetadata": {
    "alternateIds": [
      "GCVE-117-2026-0016"
    ],
    "assignerOrgId": "moksha.dk",
    "cveId": "MOKSHA-2026-0016",
    "datePublished": "2026-04-24T06:00:00Z",
    "state": "PUBLISHED",
    "x_moksha_note": "Self-issued advisory. MOKSHA-2026-NNNN is not a MITRE CVE ID. Schema follows CVE JSON 5.1 for tooling compatibility. alternateIds contains GCVE cross-references (GNA #117) and will also carry MITRE CVE IDs if assigned."
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.



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.