UBUNTU-CVE-2026-52687

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Source
https://ubuntu.com/security/CVE-2026-52687
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52687.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-52687
Upstream
  • CVE-2026-52687
Published
2026-08-28T00:00:00Z
Modified
2026-09-02T19:36:25Z
Severity
  • 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

An attacker that has valid credentials can select a compression algorithm for the IMAP connection whose decompression state requires a large amount of memory, and open several such connections. The memory limit of the process is reached with only a few connections, terminating the process and all connections it handles, which can cause degradation or denial of service for IMAP. Disable IMAP compression. Alternatively limit the number of connections handled by a single imap-login process, though this has a performance impact. 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
0 Unknown 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_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",
            "binary_version": "1:2.2.22-1ubuntu2.14"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52687.json"
Ubuntu:18.04:LTS
dovecot

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown 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_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",
            "binary_version": "1:2.2.33.2-1ubuntu4.8"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52687.json"
Ubuntu:20.04:LTS
dovecot

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown 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_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",
            "binary_version": "1:2.3.7.2-1ubuntu3.7"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52687.json"
Ubuntu:22.04:LTS
dovecot

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown 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_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",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.9"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52687.json"
Ubuntu:24.04:LTS
dovecot

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown 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_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",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.5"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52687.json"
Ubuntu:26.04:LTS
dovecot

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown 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_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",
            "binary_version": "1:2.4.2+dfsg1-3ubuntu2.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52687.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
0 Unknown 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_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",
            "binary_version": "1:2.2.9-1ubuntu2.6+esm4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-52687.json"