High
busybox — security advisory
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.
- Products
- busybox
- Affected versions
- 1:1.35.0-4, 1:1.35.0-4+deb12u1, 1:1.36.0-1~exp1, 1:1.36.1-1, 1:1.36.1-2, 1:1.36.1-3, 1:1.36.1-3.1, 1:1.36.1-4, 1:1.36.1-5, 1:1.36.1-6, 1:1.36.1-6~exp.1, 1:1.36.1-7, 1:1.36.1-8, 1:1.36.1-9, 1:1.37.0-1, 1:1.37.0-10, 1:1.37.0-10.1, 1:1.37.0-2, 1:1.37.0-3, 1:1.37.0-4, 1:1.37.0-5, 1:1.37.0-6, 1:1.37.0-7, 1:1.37.0-8, 1:1.37.0-9, 1:1.38.0-1, 1:1.38.0-2, 1:1.38.0-3
- Fixed versions
- Not specified
- CVEs
- CVE-2026-90954
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 22:57 UTC · Revision 1
Source evidence
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.
osv:DEBIAN-CVE-2026-90954
busybox
Fixed versions: Not specified
busybox
Fixed versions: Not specified
busybox
Fixed versions: Not specified
Complete source record
{
"id": "417c2c12de44a851ea37ac78deaa433626b7c9229738adf3762c72551b9e7df0",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-90954",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-90954",
"summary": "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.",
"evidence": "osv:DEBIAN-CVE-2026-90954",
"products": [
{
"name": {
"value": "busybox",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1:1.35.0-4",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.35.0-4+deb12u1",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.36.0-1~exp1",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.36.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.36.1-2",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.36.1-3",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.36.1-3.1",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.36.1-4",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.36.1-5",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.36.1-6",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.36.1-6~exp.1",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.36.1-7",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.36.1-8",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.36.1-9",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.37.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.37.0-10",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.37.0-10.1",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.37.0-2",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.37.0-3",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.37.0-4",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.37.0-5",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.37.0-6",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.37.0-7",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.37.0-8",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.37.0-9",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.38.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.38.0-2",
"evidence": "/affected/0/versions"
},
{
"value": "1:1.38.0-3",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "busybox",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1:1.37.0-10",
"evidence": "/affected/1/versions"
},
{
"value": "1:1.37.0-10.1",
"evidence": "/affected/1/versions"
},
{
"value": "1:1.37.0-6",
"evidence": "/affected/1/versions"
},
{
"value": "1:1.37.0-7",
"evidence": "/affected/1/versions"
},
{
"value": "1:1.37.0-8",
"evidence": "/affected/1/versions"
},
{
"value": "1:1.37.0-9",
"evidence": "/affected/1/versions"
},
{
"value": "1:1.38.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "1:1.38.0-2",
"evidence": "/affected/1/versions"
},
{
"value": "1:1.38.0-3",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "busybox",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1:1.37.0-10",
"evidence": "/affected/2/versions"
},
{
"value": "1:1.37.0-10.1",
"evidence": "/affected/2/versions"
},
{
"value": "1:1.37.0-6",
"evidence": "/affected/2/versions"
},
{
"value": "1:1.37.0-7",
"evidence": "/affected/2/versions"
},
{
"value": "1:1.37.0-8",
"evidence": "/affected/2/versions"
},
{
"value": "1:1.37.0-9",
"evidence": "/affected/2/versions"
},
{
"value": "1:1.38.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "1:1.38.0-2",
"evidence": "/affected/2/versions"
},
{
"value": "1:1.38.0-3",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2026-90954",
"aliases": [
"DEBIAN-CVE-2026-90954"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "busybox",
"purl": "pkg:deb/debian/busybox?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"1:1.35.0-4",
"1:1.35.0-4+deb12u1",
"1:1.36.0-1~exp1",
"1:1.36.1-1",
"1:1.36.1-2",
"1:1.36.1-3",
"1:1.36.1-3.1",
"1:1.36.1-4",
"1:1.36.1-5",
"1:1.36.1-6",
"1:1.36.1-6~exp.1",
"1:1.36.1-7",
"1:1.36.1-8",
"1:1.36.1-9",
"1:1.37.0-1",
"1:1.37.0-10",
"1:1.37.0-10.1",
"1:1.37.0-2",
"1:1.37.0-3",
"1:1.37.0-4",
"1:1.37.0-5",
"1:1.37.0-6",
"1:1.37.0-7",
"1:1.37.0-8",
"1:1.37.0-9",
"1:1.38.0-1",
"1:1.38.0-2",
"1:1.38.0-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-90954.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "busybox",
"purl": "pkg:deb/debian/busybox?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"1:1.37.0-10",
"1:1.37.0-10.1",
"1:1.37.0-6",
"1:1.37.0-7",
"1:1.37.0-8",
"1:1.37.0-9",
"1:1.38.0-1",
"1:1.38.0-2",
"1:1.38.0-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-90954.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "busybox",
"purl": "pkg:deb/debian/busybox?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"1:1.37.0-10",
"1:1.37.0-10.1",
"1:1.37.0-6",
"1:1.37.0-7",
"1:1.37.0-8",
"1:1.37.0-9",
"1:1.38.0-1",
"1:1.38.0-2",
"1:1.38.0-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-90954.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T17:47:30.585902925Z",
"provider": "osv",
"upstream": [
"CVE-2026-90954"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-90954"
]
},
"related_cves": [
{
"value": "CVE-2026-90954",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 417322,
"published_at": "2026-10-14T10:17:57.297+00:00"
}