HighFix available
linux — security advisory
An issue was discovered in the Linux kernel before 4.18.7. In block/blk-core.c, there is an __blk_drain_queue() use-after-free because a certain error case is mishandled.
- Products
- linux
- Affected versions
- Not specified
- Fixed versions
- 4.18.8-1
- CVEs
- CVE-2018-20856
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 00:12 UTC · Revision 1
Source evidence
An issue was discovered in the Linux kernel before 4.18.7. In block/blk-core.c, there is an __blk_drain_queue() use-after-free because a certain error case is mishandled.
osv:DEBIAN-CVE-2018-20856
linux
Fixed versions: 4.18.8-1
linux
Fixed versions: 4.18.8-1
linux
Fixed versions: 4.18.8-1
Complete source record
{
"id": "920c6e73c77ecf5f848d2bd95d0bef76f6d64e49df3a32eecd3a7275ff0c87da",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2018-20856",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2018-20856",
"summary": "An issue was discovered in the Linux kernel before 4.18.7. In block/blk-core.c, there is an __blk_drain_queue() use-after-free because a certain error case is mishandled.",
"evidence": "osv:DEBIAN-CVE-2018-20856",
"products": [
{
"name": {
"value": "linux",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.18.8-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "linux",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.18.8-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
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"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
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"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2018-20856",
"aliases": [
"DEBIAN-CVE-2018-20856"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.18.8-1"
}
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],
"package": {
"name": "linux",
"purl": "pkg:deb/debian/linux?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-20856.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
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{
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],
"package": {
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"purl": "pkg:deb/debian/linux?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-20856.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.18.8-1"
}
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}
],
"package": {
"name": "linux",
"purl": "pkg:deb/debian/linux?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-20856.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T18:03:05.597422050Z",
"provider": "osv",
"upstream": [
"CVE-2018-20856"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2018-20856"
]
},
"related_cves": [
{
"value": "CVE-2018-20856",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 420384,
"published_at": "2019-07-26T05:15:10.517+00:00"
}