CVE-2026-90954
Full vulnerability record from the local CVENow database.
Description
A flaw was found in BusyBox's dpkg-deb archive extraction. The ar archive handler flushes deferred symlinks after each archive member, unlike the tar, cpio, and unzip handlers which flush once after the last member. A specially crafted .deb archive with two data.tar members can exploit this ordering: the first member declares a symlink pointing to an absolute path (e.g., '/'), which is deferred as unsafe but flushed after the first member. The second member declares a regular file whose path traverses the now-live symlink, resulting in a file being written outside the intended extraction directory. This could allow an attacker to write arbitrary files to arbitrary locations when a user extracts a crafted .deb package.
View original CVE JSON
{
"id": "CVE-2026-90954",
"sourceIdentifier": "[email protected]",
"published": "2026-10-14T10:17:57.297",
"lastModified": "2026-10-19T20:21:10.970",
"vulnStatus": "Awaiting Analysis",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in BusyBox's dpkg-deb archive extraction. The ar archive handler flushes deferred symlinks after each archive member, unlike the tar, cpio, and unzip handlers which flush once after the last member. A specially crafted .deb archive with two data.tar members can exploit this ordering: the first member declares a symlink pointing to an absolute path (e.g., '/'), which is deferred as unsafe but flushed after the first member. The second member declares a regular file whose path traverses the now-live symlink, resulting in a file being written outside the intended extraction directory. This could allow an attacker to write arbitrary files to arbitrary locations when a user extracts a crafted .deb package."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "Red Hat",
"product": "Red Hat Hardened Images",
"defaultStatus": "affected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "busybox",
"cpes": [
"cpe:/a:redhat:hummingbird:1"
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "REQUIRED",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-19T19:04:23.866850Z",
"id": "CVE-2026-90954",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-59"
}
]
}
],
"references": [
{
"url": "https://access.redhat.com/security/cve/CVE-2026-90954",
"source": "[email protected]"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2533007",
"source": "[email protected]"
}
]
}