UBUNTU-CVE-2026-42395

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Source
https://ubuntu.com/security/CVE-2026-42395
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42395.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-42395
Upstream
  • CVE-2026-42395
Published
2026-08-28T00:00:00Z
Modified
2026-09-02T19:36:05.342256540Z
Severity
  • 4.3 (Medium) CVSS_V3 - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

A host listed as a trusted proxy can send forwarding information containing a NUL byte, which crashes the login process on the following login attempt. The login process is terminated, which can cause degradation or denial of service for logins. Deployments that do not configure trusted proxies are not affected. Restrict the list of trusted proxy networks to hosts that are fully under your control. Update to non-vulnerable version. No publicly available exploits are known.

References

Affected packages

Ubuntu:16.04:LTS
dovecot

Package

Name
dovecot
Purl
pkg:deb/ubuntu/dovecot?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1:2.*
1:2.2.18-2ubuntu2
1:2.2.22-1ubuntu1
1:2.2.22-1ubuntu2
1:2.2.22-1ubuntu2.1
1:2.2.22-1ubuntu2.2
1:2.2.22-1ubuntu2.3
1:2.2.22-1ubuntu2.4
1:2.2.22-1ubuntu2.6
1:2.2.22-1ubuntu2.7
1:2.2.22-1ubuntu2.8
1:2.2.22-1ubuntu2.9
1:2.2.22-1ubuntu2.10
1:2.2.22-1ubuntu2.11
1:2.2.22-1ubuntu2.12
1:2.2.22-1ubuntu2.13
1:2.2.22-1ubuntu2.14

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-core"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-gssapi"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-imapd"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-ldap"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-lmtpd"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-lucene"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-managesieved"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-mysql"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-pgsql"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-pop3d"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-sieve"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-solr"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "dovecot-sqlite"
        },
        {
            "binary_version": "1:2.2.22-1ubuntu2.14",
            "binary_name": "mail-stack-delivery"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42395.json"
Ubuntu:18.04:LTS
dovecot

Package

Name
dovecot
Purl
pkg:deb/ubuntu/dovecot?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1:2.*
1:2.2.27-3ubuntu1
1:2.2.33.2-1ubuntu1
1:2.2.33.2-1ubuntu2
1:2.2.33.2-1ubuntu3
1:2.2.33.2-1ubuntu4
1:2.2.33.2-1ubuntu4.1
1:2.2.33.2-1ubuntu4.2
1:2.2.33.2-1ubuntu4.3
1:2.2.33.2-1ubuntu4.4
1:2.2.33.2-1ubuntu4.5
1:2.2.33.2-1ubuntu4.6
1:2.2.33.2-1ubuntu4.7
1:2.2.33.2-1ubuntu4.8

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "dovecot-core"
        },
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "dovecot-gssapi"
        },
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "dovecot-imapd"
        },
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "dovecot-ldap"
        },
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "dovecot-lmtpd"
        },
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "dovecot-managesieved"
        },
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "dovecot-mysql"
        },
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "dovecot-pgsql"
        },
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "dovecot-pop3d"
        },
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "dovecot-sieve"
        },
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "dovecot-solr"
        },
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "dovecot-sqlite"
        },
        {
            "binary_version": "1:2.2.33.2-1ubuntu4.8",
            "binary_name": "mail-stack-delivery"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42395.json"
Ubuntu:20.04:LTS
dovecot

Package

Name
dovecot
Purl
pkg:deb/ubuntu/dovecot?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1:2.*
1:2.3.4.1-5ubuntu3
1:2.3.7.2-1ubuntu1
1:2.3.7.2-1ubuntu2
1:2.3.7.2-1ubuntu3
1:2.3.7.2-1ubuntu3.1
1:2.3.7.2-1ubuntu3.2
1:2.3.7.2-1ubuntu3.3
1:2.3.7.2-1ubuntu3.4
1:2.3.7.2-1ubuntu3.5
1:2.3.7.2-1ubuntu3.6
1:2.3.7.2-1ubuntu3.7

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-auth-lua"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-core"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-gssapi"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-imapd"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-ldap"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-lmtpd"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-lucene"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-managesieved"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-mysql"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-pgsql"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-pop3d"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-sieve"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-solr"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-sqlite"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "dovecot-submissiond"
        },
        {
            "binary_version": "1:2.3.7.2-1ubuntu3.7",
            "binary_name": "mail-stack-delivery"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42395.json"
Ubuntu:22.04:LTS
dovecot

Package

Name
dovecot
Purl
pkg:deb/ubuntu/dovecot?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1:2.*
1:2.3.13+dfsg1-1ubuntu3
1:2.3.16+dfsg1-3ubuntu1
1:2.3.16+dfsg1-3ubuntu2
1:2.3.16+dfsg1-3ubuntu2.1
1:2.3.16+dfsg1-3ubuntu2.2
1:2.3.16+dfsg1-3ubuntu2.4
1:2.3.16+dfsg1-3ubuntu2.6
1:2.3.16+dfsg1-3ubuntu2.7
1:2.3.16+dfsg1-3ubuntu2.8
1:2.3.16+dfsg1-3ubuntu2.9

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-auth-lua"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-core"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-gssapi"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-imapd"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-ldap"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-lmtpd"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-lucene"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-managesieved"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-mysql"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-pgsql"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-pop3d"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-sieve"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-solr"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-sqlite"
        },
        {
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9",
            "binary_name": "dovecot-submissiond"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42395.json"
Ubuntu:24.04:LTS
dovecot

Package

Name
dovecot
Purl
pkg:deb/ubuntu/dovecot?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1:2.*
1:2.3.20+dfsg1-1ubuntu3
1:2.3.21+dfsg1-2ubuntu1
1:2.3.21+dfsg1-2ubuntu2
1:2.3.21+dfsg1-2ubuntu4
1:2.3.21+dfsg1-2ubuntu5
1:2.3.21+dfsg1-2ubuntu6
1:2.3.21+dfsg1-2ubuntu6.1
1:2.3.21+dfsg1-2ubuntu6.2
1:2.3.21+dfsg1-2ubuntu6.3
1:2.3.21+dfsg1-2ubuntu6.4
1:2.3.21+dfsg1-2ubuntu6.5

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-auth-lua"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-core"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-gssapi"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-imapd"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-ldap"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-lmtpd"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-managesieved"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-mysql"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-pgsql"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-pop3d"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-sieve"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-solr"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-sqlite"
        },
        {
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5",
            "binary_name": "dovecot-submissiond"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42395.json"
Ubuntu:26.04:LTS
dovecot

Package

Name
dovecot
Purl
pkg:deb/ubuntu/dovecot?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1:2.*
1:2.4.1+dfsg1-5ubuntu4
1:2.4.1+dfsg1-5ubuntu5
1:2.4.2+dfsg1-3ubuntu1
1:2.4.2+dfsg1-3ubuntu2
1:2.4.2+dfsg1-3ubuntu2.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-auth-lua"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-core"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-flatcurve"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-gssapi"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-imapd"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-ldap"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-lmtpd"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-managesieved"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-mysql"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-pgsql"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-pop3d"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-sieve"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-solr"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-sqlite"
        },
        {
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1",
            "binary_name": "dovecot-submissiond"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42395.json"
Ubuntu:Pro:14.04:LTS
dovecot

Package

Name
dovecot
Purl
pkg:deb/ubuntu/dovecot?arch=source&distro=esm-infra-legacy%2Ftrusty

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1:2.*
1:2.1.7-7ubuntu3
1:2.2.9-1ubuntu1
1:2.2.9-1ubuntu2
1:2.2.9-1ubuntu2.1
1:2.2.9-1ubuntu2.3
1:2.2.9-1ubuntu2.4
1:2.2.9-1ubuntu2.5
1:2.2.9-1ubuntu2.6
1:2.2.9-1ubuntu2.6+esm1
1:2.2.9-1ubuntu2.6+esm2
1:2.2.9-1ubuntu2.6+esm3
1:2.2.9-1ubuntu2.6+esm4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "dovecot-core"
        },
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "dovecot-gssapi"
        },
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "dovecot-imapd"
        },
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "dovecot-ldap"
        },
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "dovecot-lmtpd"
        },
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "dovecot-managesieved"
        },
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "dovecot-mysql"
        },
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "dovecot-pgsql"
        },
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "dovecot-pop3d"
        },
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "dovecot-sieve"
        },
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "dovecot-solr"
        },
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "dovecot-sqlite"
        },
        {
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4",
            "binary_name": "mail-stack-delivery"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42395.json"