mosquitto — security advisory
When Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use an ACL file, and that ACL file is empty, or contains only comments or blank lines, then Mosquitto will treat this as though no ACL file has been defined and use a default allow policy. The new behaviour is to have an empty ACL file mean that all access is denied, which is not a useful configuration but is not unexpected.
- Products
- mosquitto
- Affected versions
- Not specified
- Fixed versions
- 1.5.6-1
- CVEs
- CVE-2018-12550
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 00:41 UTC · Revision 1
Source evidence
When Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use an ACL file, and that ACL file is empty, or contains only comments or blank lines, then Mosquitto will treat this as though no ACL file has been defined and use a default allow policy. The new behaviour is to have an empty ACL file mean that all access is denied, which is not a useful configuration but is not unexpected.
osv:DEBIAN-CVE-2018-12550
mosquitto
Fixed versions: 1.5.6-1
mosquitto
Fixed versions: 1.5.6-1
mosquitto
Fixed versions: 1.5.6-1
Complete source record
{
"id": "fde355f3b85e25df8dd6142394dbc2e6a391e36f5a979ba8daf55c7a73aaf752",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2018-12550",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2018-12550",
"summary": "When Eclipse Mosquitto version 1.0 to 1.5.5 (inclusive) is configured to use an ACL file, and that ACL file is empty, or contains only comments or blank lines, then Mosquitto will treat this as though no ACL file has been defined and use a default allow policy. The new behaviour is to have an empty ACL file mean that all access is denied, which is not a useful configuration but is not unexpected.",
"evidence": "osv:DEBIAN-CVE-2018-12550",
"products": [
{
"name": {
"value": "mosquitto",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.5.6-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "mosquitto",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.5.6-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "mosquitto",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1.5.6-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2018-12550",
"aliases": [
"DEBIAN-CVE-2018-12550"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.5.6-1"
}
]
}
],
"package": {
"name": "mosquitto",
"purl": "pkg:deb/debian/mosquitto?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-12550.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.5.6-1"
}
]
}
],
"package": {
"name": "mosquitto",
"purl": "pkg:deb/debian/mosquitto?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-12550.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.5.6-1"
}
]
}
],
"package": {
"name": "mosquitto",
"purl": "pkg:deb/debian/mosquitto?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2018-12550.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T18:03:36.428360808Z",
"provider": "osv",
"upstream": [
"CVE-2018-12550"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2018-12550"
]
},
"related_cves": [
{
"value": "CVE-2018-12550",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 421968,
"published_at": "2019-03-27T18:29:00.303+00:00"
}