CVE-2026-93834
Full vulnerability record from the local CVENow database.
Description
A use-after-free vulnerability was found in QEMU's 9pfs subsystem. A race condition between the main thread and a worker thread when processing concurrent Tlcreate and Twalk requests allows a malicious guest user to craft a fid path containing stale heap data, bypassing directory traversal restrictions and escaping the shared directory boundary. This can lead to arbitrary host file read/write and code execution (VM escape) as the QEMU process user.
Severity
HIGH
CVSS score
8.8
(v3.1)
Vulnerability status
Awaiting Analysis
Source identifier
Published
2026-09-25 14:17:24.063000
Last modified
2026-10-31 08:16:49.610000
View original CVE JSON
{
"id": "CVE-2026-93834",
"sourceIdentifier": "[email protected]",
"published": "2026-09-25T14:17:24.063",
"lastModified": "2026-10-31T08:16:49.610",
"vulnStatus": "Awaiting Analysis",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "A use-after-free vulnerability was found in QEMU's 9pfs subsystem. A race condition between the main thread and a worker thread when processing concurrent Tlcreate and Twalk requests allows a malicious guest user to craft a fid path containing stale heap data, bypassing directory traversal restrictions and escaping the shared directory boundary. This can lead to arbitrary host file read/write and code execution (VM escape) as the QEMU process user."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 10",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "qemu-kvm",
"cpes": [
"cpe:/o:redhat:enterprise_linux:10"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 6",
"defaultStatus": "unaffected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "qemu-kvm",
"cpes": [
"cpe:/o:redhat:enterprise_linux:6"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 7",
"defaultStatus": "unaffected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "qemu-kvm",
"cpes": [
"cpe:/o:redhat:enterprise_linux:7"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 7",
"defaultStatus": "unaffected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "qemu-kvm-ma",
"cpes": [
"cpe:/o:redhat:enterprise_linux:7"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 8",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "virt-devel:rhel/qemu-kvm",
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 8",
"defaultStatus": "affected",
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"packageName": "virt:rhel/qemu-kvm",
"cpes": [
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]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 9",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "qemu-kvm",
"cpes": [
"cpe:/o:redhat:enterprise_linux:9"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux for NVIDIA 26",
"defaultStatus": "unknown",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "qemu-kvm",
"cpes": [
"cpe:/a:redhat:enterprise_linux_nvidia:"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat OpenShift Container Platform 4",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "openshift/ose-rhel-coreos-8",
"cpes": [
"cpe:/a:redhat:openshift:4"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat OpenShift Container Platform 4",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "openshift/ose-rhel-coreos-9",
"cpes": [
"cpe:/a:redhat:openshift:4"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat OpenShift Container Platform 5",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "openshift/ose-rhel-coreos-9",
"cpes": [
"cpe:/a:redhat:openshift:5"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat OpenStack Platform 13 (Queens)",
"defaultStatus": "unaffected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "qemu-kvm-rhev",
"cpes": [
"cpe:/a:redhat:openstack:13"
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "CHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.0,
"impactScore": 6.0
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-09-25T13:49:32.754375Z",
"id": "CVE-2026-93834",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-416"
}
]
}
],
"references": [
{
"url": "https://access.redhat.com/security/cve/CVE-2026-93834",
"source": "[email protected]"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2537939",
"source": "[email protected]"
},
{
"url": "https://gitlab.com/qemu-project/qemu/-/work_items/4491",
"source": "[email protected]"
},
{
"url": "https://gitlab.com/qemu-project/qemu/-/work_items/4491",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
]
}