CVE-2026-77159
Full vulnerability record from the local CVENow database.
Description
A symlink-following flaw was found in libvirt's qemuTPMEmulatorPrepareHost() function. The function uses a path-based chown() on the swtpm logfile without checking for symbolic links. A local attacker with access to the swtpm account can replace the logfile with a symlink, causing libvirtd (running as root) to transfer ownership of an arbitrary file to the swtpm user.
Severity
MEDIUM
CVSS score
5.5
(v3.1)
Vulnerability status
Awaiting Analysis
Source identifier
Published
2026-09-11 11:16:54.677000
Last modified
2026-11-06 01:17:51.823000
View original CVE JSON
{
"id": "CVE-2026-77159",
"sourceIdentifier": "[email protected]",
"published": "2026-09-11T11:16:54.677",
"lastModified": "2026-11-06T01:17:51.823",
"vulnStatus": "Awaiting Analysis",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "A symlink-following flaw was found in libvirt's qemuTPMEmulatorPrepareHost() function. The function uses a path-based chown() on the swtpm logfile without checking for symbolic links. A local attacker with access to the swtpm account can replace the logfile with a symlink, causing libvirtd (running as root) to transfer ownership of an arbitrary file to the swtpm 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": "libvirt",
"cpes": [
"cpe:/a: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": "libvirt",
"cpes": [
"cpe:/o:redhat:rhel_els:6"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 7",
"defaultStatus": "unknown",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "libvirt",
"cpes": [
"cpe:/o:redhat:rhel_els:7"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 8",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "virt:rhel/libvirt",
"cpes": [
"cpe:/a:redhat:enterprise_linux:8"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Enterprise Linux 9",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "libvirt",
"cpes": [
"cpe:/a:redhat:enterprise_linux:9"
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-09-15T15:39:11.306501Z",
"id": "CVE-2026-77159",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-61"
}
]
}
],
"references": [
{
"url": "https://access.redhat.com/security/cve/CVE-2026-77159",
"source": "[email protected]"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2531811",
"source": "[email protected]"
},
{
"url": "https://gitlab.com/libvirt/libvirt/-/work_items/909",
"source": "[email protected]"
},
{
"url": "https://gitlab.com/libvirt/libvirt/-/work_items/909",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
]
}