CriticalFix available
zsh — security advisory
In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.
- Products
- zsh
- Affected versions
- Not specified
- Fixed versions
- 5.5-1
- CVEs
- CVE-2018-7548
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 00:57 UTC · Revision 1
Source evidence
In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.
osv:DEBIAN-CVE-2018-7548
zsh
Fixed versions: 5.5-1
zsh
Fixed versions: 5.5-1
zsh
Fixed versions: 5.5-1
Complete source record
{
"id": "69f1ccb7a8abeb078ee27beface2004c1a10cc560a3fdda8f5714c7fedab096e",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2018-7548",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2018-7548",
"summary": "In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.",
"evidence": "osv:DEBIAN-CVE-2018-7548",
"products": [
{
"name": {
"value": "zsh",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.5-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "zsh",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.5-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "zsh",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.5-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "critical",
"structured": {
"id": "DEBIAN-CVE-2018-7548",
"aliases": [
"DEBIAN-CVE-2018-7548"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
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{
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}
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],
"package": {
"name": "zsh",
"purl": "pkg:deb/debian/zsh?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-7548.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
},
{
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],
"package": {
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"purl": "pkg:deb/debian/zsh?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-7548.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.5-1"
}
]
}
],
"package": {
"name": "zsh",
"purl": "pkg:deb/debian/zsh?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-7548.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
}
],
"modified": "2026-10-23T18:03:58.469270746Z",
"provider": "osv",
"upstream": [
"CVE-2018-7548"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2018-7548"
]
},
"related_cves": [
{
"value": "CVE-2018-7548",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 422793,
"published_at": "2018-02-27T22:29:00.59+00:00"
}