MOKSHA-2026-0058 (moksha-2026-0058)
Vulnerability from moksha – Published: 2026-04-24 06:00 – Updated:
VLAI
Title
Xenstore Quota Exhaustion via VM.xenstore_data
Summary
A vm-admin in XAPI-based hypervisors (XenServer, XCP-ng) can exhaust a guest domain's xenstore quota by injecting a large number of vm-data/* keys into VM.xenstore_data. Xenstore enforces a per-domain quota shared with guest agent data. When injected data consumes the quota, the guest's own xenstore operations fail, disrupting PV drivers, network configuration, and guest agent communication. The field has zero map_keys_roles entries and no value length limits.
Severity
5.3 (Medium)
CWE
- CWE-400 - Uncontrolled Resource Consumption
References
1 reference
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Cloud Software Group | XenServer |
Affected:
all
(custom)
|
|
| Vates | XCP-ng |
Affected:
all
(custom)
|
Credits
{
"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 exhaust a guest domain\u0027s xenstore quota by injecting a large number of vm-data/* keys into VM.xenstore_data. Xenstore enforces a per-domain quota shared with guest agent data. When injected data consumes the quota, the guest\u0027s own xenstore operations fail, disrupting PV drivers, network configuration, and guest agent communication. The field has zero map_keys_roles entries and no value length limits."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"format": "CVSS"
},
{
"cvssV4_0": {
"baseScore": 5.3,
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L",
"version": "4.0"
},
"format": "CVSS"
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-400",
"description": "Uncontrolled Resource Consumption",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-04-24T06:00:00Z",
"orgId": "moksha.dk",
"shortName": "Moksha"
},
"references": [
{
"url": "https://cna.moksha.dk/MOKSHA-2026-0058"
}
],
"title": "Xenstore Quota Exhaustion via VM.xenstore_data"
}
},
"cveMetadata": {
"alternateIds": [
"GCVE-117-2026-0058"
],
"assignerOrgId": "moksha.dk",
"cveId": "MOKSHA-2026-0058",
"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"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
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.
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