UnratedFix available
Fix CVE(s): CVE-2026-27858
Type: advisorySources: OSV
* SECURITY UPDATE: managesieve-login pre-auth excessive memory usage DoS via oversized AUTHENTICATE initial response (ELSCVE-158963) - debian/patches/CVE-2026-27858.patch: verify the AUTHENTICATE initial response size is not too large before allocating in pigeonhole/src/managesieve-login/client-authenticate.c. Backport of upstream pigeonhole commit 54f645225a8a: the five added lines are byte-identical to upstream, while the hunk context is this tree's pre-cc1b8988 (unreformatted) layout, which is why the blob index differs from upstream's. - CVE-2026-27858
- Products
- dovecot-auth-lua, dovecot-core, dovecot-dev, dovecot-gssapi, dovecot-imapd, dovecot-ldap, dovecot-lmtpd, dovecot-lucene, dovecot-managesieved, dovecot-mysql, dovecot-pgsql, dovecot-pop3d, dovecot-sieve, dovecot-solr, dovecot-sqlite, dovecot-submissiond, mail-stack-delivery
- Affected versions
- Not specified
- Fixed versions
- 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
- CVEs
- CVE-2026-27858
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 10:59 UTC · Revision 1
Source evidence
* SECURITY UPDATE: managesieve-login pre-auth excessive memory usage DoS via oversized AUTHENTICATE initial response (ELSCVE-158963) - debian/patches/CVE-2026-27858.patch: verify the AUTHENTICATE initial response size is not too large before allocating in pigeonhole/src/managesieve-login/client-authenticate.c. Backport of upstream pigeonhole commit 54f645225a8a: the five added lines are byte-identical to upstream, while the hunk context is this tree's pre-cc1b8988 (unreformatted) layout, which is why the blob index differs from upstream's. - CVE-2026-27858
osv:CLSA-2026-1785836865
dovecot-auth-lua
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-core
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-dev
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-gssapi
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-imapd
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-ldap
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-lmtpd
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-lucene
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-managesieved
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-mysql
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-pgsql
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-pop3d
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-sieve
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-solr
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-sqlite
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
dovecot-submissiond
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
mail-stack-delivery
Fixed versions: 1:2.3.7.2-1ubuntu3.7+tuxcare.els3
Complete source record
{
"id": "9fb809d5d81dbad545ba3ab788b06801345586f534d98ae5db640859ceff22bf",
"url": "https://osv.dev/vulnerability/CLSA-2026-1785836865",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Fix CVE(s): CVE-2026-27858",
"summary": "* SECURITY UPDATE: managesieve-login pre-auth excessive memory usage DoS via oversized AUTHENTICATE initial response (ELSCVE-158963) - debian/patches/CVE-2026-27858.patch: verify the AUTHENTICATE initial response size is not too large before allocating in pigeonhole/src/managesieve-login/client-authenticate.c. Backport of upstream pigeonhole commit 54f645225a8a: the five added lines are byte-identical to upstream, while the hunk context is this tree's pre-cc1b8988 (unreformatted) layout, which is why the blob index differs from upstream's. - CVE-2026-27858",
"evidence": "osv:CLSA-2026-1785836865",
"products": [
{
"name": {
"value": "dovecot-auth-lua",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-core",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-dev",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-gssapi",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-imapd",
"evidence": "/affected/4/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/4/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-ldap",
"evidence": "/affected/5/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/5/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-lmtpd",
"evidence": "/affected/6/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/6/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-lucene",
"evidence": "/affected/7/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/7/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-managesieved",
"evidence": "/affected/8/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/8/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-mysql",
"evidence": "/affected/9/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/9/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-pgsql",
"evidence": "/affected/10/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/10/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-pop3d",
"evidence": "/affected/11/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/11/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-sieve",
"evidence": "/affected/12/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/12/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-solr",
"evidence": "/affected/13/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/13/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-sqlite",
"evidence": "/affected/14/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/14/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "dovecot-submissiond",
"evidence": "/affected/15/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/15/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "mail-stack-delivery",
"evidence": "/affected/16/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3",
"evidence": "/affected/16/ranges"
}
],
"affected_versions": []
}
],
"severity": "unknown",
"structured": {
"id": "CLSA-2026-1785836865",
"aliases": [
"CLSA-2026-1785836865"
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-auth-lua",
"purl": "pkg:deb/tuxcare/dovecot-auth-lua?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-core",
"purl": "pkg:deb/tuxcare/dovecot-core?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-dev",
"purl": "pkg:deb/tuxcare/dovecot-dev?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-gssapi",
"purl": "pkg:deb/tuxcare/dovecot-gssapi?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-imapd",
"purl": "pkg:deb/tuxcare/dovecot-imapd?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-ldap",
"purl": "pkg:deb/tuxcare/dovecot-ldap?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-lmtpd",
"purl": "pkg:deb/tuxcare/dovecot-lmtpd?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-lucene",
"purl": "pkg:deb/tuxcare/dovecot-lucene?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-managesieved",
"purl": "pkg:deb/tuxcare/dovecot-managesieved?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-mysql",
"purl": "pkg:deb/tuxcare/dovecot-mysql?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-pgsql",
"purl": "pkg:deb/tuxcare/dovecot-pgsql?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-pop3d",
"purl": "pkg:deb/tuxcare/dovecot-pop3d?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-sieve",
"purl": "pkg:deb/tuxcare/dovecot-sieve?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-solr",
"purl": "pkg:deb/tuxcare/dovecot-solr?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-sqlite",
"purl": "pkg:deb/tuxcare/dovecot-sqlite?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "dovecot-submissiond",
"purl": "pkg:deb/tuxcare/dovecot-submissiond?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "1:2.3.7.2-1ubuntu3.7+tuxcare.els3"
}
]
}
],
"package": {
"name": "mail-stack-delivery",
"purl": "pkg:deb/tuxcare/mail-stack-delivery?distro=ubuntu-20.04",
"ecosystem": "TuxCare:Ubuntu:20.04"
},
"database_specific": {
"source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/ubuntu20.04els/CLSA-2026-1785836865.json"
}
}
],
"modified": "2026-10-26T09:31:40.147008151Z",
"provider": "osv",
"upstream": [
"CVE-2026-27858"
],
"references": [
"https://errata.tuxcare.com/els_os/ubuntu20.04els/CLSA-2026-1785836865.html",
"https://nvd.nist.gov/vuln/detail/CVE-2026-27858"
]
},
"related_cves": [
{
"value": "CVE-2026-27858",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": null
},
"source_id": "core-osv",
"document_id": 448025,
"published_at": "2026-08-04T09:48:01+00:00"
}