UBUNTU-CVE-2026-27856

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Source

https://ubuntu.com/security/CVE-2026-27856

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27856.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-27856

Upstream

CVE-2026-27856

Related

USN-8136-1

Published

2026-03-27T00:00:00Z

Modified

2026-04-22T16:27:39.443009Z

Severity

7.4 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

Doveadm credentials are verified using direct comparison which is susceptible to timing oracle attack. An attacker can use this to determine the configured credentials. Figuring out the credential will lead into full access to the affected component. Limit access to the doveadm http service port, install fixed version. No publicly available exploits are known.

References

Affected packages

Ubuntu:20.04:LTS / dovecot

Package

Name: dovecot
Purl: pkg:deb/ubuntu/dovecot@1:2.3.7.2-1ubuntu3.7?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_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-2026-27856.json"

Ubuntu:22.04:LTS / dovecot

Package

Name: dovecot
Purl: pkg:deb/ubuntu/dovecot@1:2.3.16+dfsg1-3ubuntu2.7?arch=source&distro=jammy

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

1:2.3.16+dfsg1-3ubuntu2.7

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

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "dovecot-auth-lua",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-core",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-gssapi",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-imapd",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-ldap",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-lmtpd",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-lucene",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-managesieved",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-mysql",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-pgsql",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-pop3d",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-sieve",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-solr",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-sqlite",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        },
        {
            "binary_name": "dovecot-submissiond",
            "binary_version": "1:2.3.16+dfsg1-3ubuntu2.7"
        }
    ],
    "availability": "No subscription required"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27856.json"

Ubuntu:24.04:LTS / dovecot

Package

Name: dovecot
Purl: pkg:deb/ubuntu/dovecot@1:2.3.21+dfsg1-2ubuntu6.3?arch=source&distro=noble

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

1:2.3.21+dfsg1-2ubuntu6.3

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

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "dovecot-auth-lua",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-core",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-gssapi",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-imapd",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-ldap",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-lmtpd",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-managesieved",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-mysql",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-pgsql",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-pop3d",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-sieve",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-solr",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-sqlite",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        },
        {
            "binary_name": "dovecot-submissiond",
            "binary_version": "1:2.3.21+dfsg1-2ubuntu6.3"
        }
    ],
    "availability": "No subscription required"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27856.json"

Ubuntu:25.10 / dovecot

Package

Name: dovecot
Purl: pkg:deb/ubuntu/dovecot@1:2.4.1+dfsg1-5ubuntu4.1?arch=source&distro=questing

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

1:2.4.1+dfsg1-5ubuntu4.1

Affected versions

1:2.*

1:2.3.21.1+dfsg1-1ubuntu2

1:2.4.1+dfsg1-5ubuntu1

1:2.4.1+dfsg1-5ubuntu3

1:2.4.1+dfsg1-5ubuntu4

Ecosystem specific

{
    "binaries": [
        {
            "binary_name": "dovecot-auth-lua",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-core",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-flatcurve",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-gssapi",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-imapd",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-ldap",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-lmtpd",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-managesieved",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-mysql",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-pgsql",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-pop3d",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-sieve",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-solr",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-sqlite",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        },
        {
            "binary_name": "dovecot-submissiond",
            "binary_version": "1:2.4.1+dfsg1-5ubuntu4.1"
        }
    ],
    "availability": "No subscription required"
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-27856.json"