HighFix available
dovecot — security advisory
Dovecot SQL based authentication can be bypassed when auth_username_chars is cleared by admin. This vulnerability allows bypassing authentication for any user and user enumeration. Do not clear auth_username_chars. If this is not possible, install latest fixed version. No publicly available exploits are known.
- Products
- dovecot
- Affected versions
- 1:2.4.1+dfsg1-6, 1:2.4.1+dfsg1-6+deb13u1, 1:2.4.1+dfsg1-6+deb13u2, 1:2.4.1+dfsg1-6+deb13u3, 1:2.4.1+dfsg1-7, 1:2.4.1+dfsg1-8, 1:2.4.1+dfsg1-9, 1:2.4.2+dfsg1-1, 1:2.4.2+dfsg1-2, 1:2.4.2+dfsg1-3, 1:2.4.2+dfsg1-4
- Fixed versions
- 1:2.4.1+dfsg1-6+deb13u4, 1:2.4.3+dfsg1-1
- CVEs
- CVE-2026-24031
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 17:37 UTC · Revision 2
Source evidence
Dovecot SQL based authentication can be bypassed when auth_username_chars is cleared by admin. This vulnerability allows bypassing authentication for any user and user enumeration. Do not clear auth_username_chars. If this is not possible, install latest fixed version. No publicly available exploits are known.
osv:DEBIAN-CVE-2026-24031
dovecot
Fixed versions: 1:2.4.1+dfsg1-6+deb13u4
dovecot
Fixed versions: 1:2.4.3+dfsg1-1
Complete source record
{
"id": "d84622921d1b24f4c6ff8fb4a22cd28ddf87ca47197540a88f3d7cd7b350b122",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-24031",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-24031",
"summary": "Dovecot SQL based authentication can be bypassed when auth_username_chars is cleared by admin. This vulnerability allows bypassing authentication for any user and user enumeration. Do not clear auth_username_chars. If this is not possible, install latest fixed version. No publicly available exploits are known.",
"evidence": "osv:DEBIAN-CVE-2026-24031",
"products": [
{
"name": {
"value": "dovecot",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.4.1+dfsg1-6+deb13u4",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "1:2.4.1+dfsg1-6",
"evidence": "/affected/0/versions"
},
{
"value": "1:2.4.1+dfsg1-6+deb13u1",
"evidence": "/affected/0/versions"
},
{
"value": "1:2.4.1+dfsg1-6+deb13u2",
"evidence": "/affected/0/versions"
},
{
"value": "1:2.4.1+dfsg1-6+deb13u3",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "dovecot",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.4.3+dfsg1-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": [
{
"value": "1:2.4.1+dfsg1-6",
"evidence": "/affected/1/versions"
},
{
"value": "1:2.4.1+dfsg1-7",
"evidence": "/affected/1/versions"
},
{
"value": "1:2.4.1+dfsg1-8",
"evidence": "/affected/1/versions"
},
{
"value": "1:2.4.1+dfsg1-9",
"evidence": "/affected/1/versions"
},
{
"value": "1:2.4.2+dfsg1-1",
"evidence": "/affected/1/versions"
},
{
"value": "1:2.4.2+dfsg1-2",
"evidence": "/affected/1/versions"
},
{
"value": "1:2.4.2+dfsg1-3",
"evidence": "/affected/1/versions"
},
{
"value": "1:2.4.2+dfsg1-4",
"evidence": "/affected/1/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2026-24031",
"aliases": [
"DEBIAN-CVE-2026-24031"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.4.1+dfsg1-6+deb13u4"
}
]
}
],
"package": {
"name": "dovecot",
"purl": "pkg:deb/debian/dovecot?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"1:2.4.1+dfsg1-6",
"1:2.4.1+dfsg1-6+deb13u1",
"1:2.4.1+dfsg1-6+deb13u2",
"1:2.4.1+dfsg1-6+deb13u3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-24031.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.4.3+dfsg1-1"
}
]
}
],
"package": {
"name": "dovecot",
"purl": "pkg:deb/debian/dovecot?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"1:2.4.1+dfsg1-6",
"1:2.4.1+dfsg1-7",
"1:2.4.1+dfsg1-8",
"1:2.4.1+dfsg1-9",
"1:2.4.2+dfsg1-1",
"1:2.4.2+dfsg1-2",
"1:2.4.2+dfsg1-3",
"1:2.4.2+dfsg1-4"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-24031.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-27T09:47:32.257476306Z",
"provider": "osv",
"upstream": [
"CVE-2026-24031"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-24031"
]
},
"related_cves": [
{
"value": "CVE-2026-24031",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 460905,
"published_at": "2026-03-27T09:16:19.447+00:00"
}