Packages
- dovecot - IMAP and POP3 email server
Details
It was discovered that Dovecot incorrectly treated some variable expansion
pipelines as safe in authentication filters. An attacker could possibly use
this issue to perform SQL or LDAP injection attacks. This issue only
affected Ubuntu 25.10 and Ubuntu 26.04 LTS. (CVE-2026-27851)
It was discovered that Dovecot incorrectly verified SCRAM TLS channel
binding in certain base64 exchanges. A remote attacker could possibly use
this issue to obtain sensitive information in a machine-in-the-middle
attack. (CVE-2026-33603)
It was discovered that Dovecot incorrectly enforced Sieve script CPU
limits. An attacker could possibly use this issue to cause Dovecot to use
excessive resources, leading to a denial of service. (CVE-2026-40016)
It was discovered that Dovecot incorrectly handled certain IMAP SETACL
commands. An...
It was discovered that Dovecot incorrectly treated some variable expansion
pipelines as safe in authentication filters. An attacker could possibly use
this issue to perform SQL or LDAP injection attacks. This issue only
affected Ubuntu 25.10 and Ubuntu 26.04 LTS. (CVE-2026-27851)
It was discovered that Dovecot incorrectly verified SCRAM TLS channel
binding in certain base64 exchanges. A remote attacker could possibly use
this issue to obtain sensitive information in a machine-in-the-middle
attack. (CVE-2026-33603)
It was discovered that Dovecot incorrectly enforced Sieve script CPU
limits. An attacker could possibly use this issue to cause Dovecot to use
excessive resources, leading to a denial of service. (CVE-2026-40016)
It was discovered that Dovecot incorrectly handled certain IMAP SETACL
commands. An attacker could possibly use this issue to spam folders to
other users. (CVE-2026-40020)
It was discovered that Dovecot incorrectly handled excessive IMAP bracing.
An attacker could possibly use this issue to cause Dovecot to use excessive
resources, leading to a denial of service. (CVE-2026-42006)
Update instructions
In general, a standard system update will make all the necessary changes.
Learn more about how to get the fixes.The problem can be corrected by updating your system to the following package versions:
| Ubuntu Release | Package Version | ||
|---|---|---|---|
| 26.04 LTS resolute | dovecot-core – 1:2.4.2+dfsg1-3ubuntu2.1 | ||
| 25.10 questing | dovecot-core – 1:2.4.1+dfsg1-5ubuntu4.2 | ||
| 24.04 LTS noble | dovecot-core – 1:2.3.21+dfsg1-2ubuntu6.5 | ||
| 22.04 LTS jammy | dovecot-core – 1:2.3.16+dfsg1-3ubuntu2.9 | ||
Reduce your security exposure
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