Ubuntu USN · USN-8136-2

Dovecot regression

Published: Tue, 28 Apr 2026 12:52

CVE-2026-0394

Summary

USN-8136-1 introduced a regression in Dovecot

Details

USN-8136-1 fixed vulnerabilities in Dovecot. The update caused a regression on Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. This update fixes the problem. We apologize for the inconvenience. Original advisory details: It was discovered that Dovecot incorrectly handled invalid base64 SASL data. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 25.10. (CVE-2025-59028) It was discovered that Dovecot script decode2text.sh incorrectly handled zip files. An attacker could possibly use this issue to obtain sensitive information. (CVE-2025-59031) It was discovered that Dovecot incorrectly handled certain AUTHENTICATE requests. An attacker could possibly use this issue to cause a denial of service. (CVE-2025-59032) It was discovered that Dovecot incorrectly handled certain SQL based authentication. An attacker could possibly use this issue to bypass authentication. This issue only affected Ubuntu 25.10. (CVE-2026-24031) It was discovered that Dovecot incorrectly handled certain LDAP based authentication. An attacker could possibly use this issue to bypass restrictions and allow probing of LDAP structure. This issue only affected Ubuntu 25.10. (CVE-2026-27860) It was discovered that Dovecot is vulnerable to replay attack under certain conditions. An attacker could possibly use this issue to bypass authentication. (CVE-2026-27855) It was discovered that Dovecot is vulnerable to a timing attack under certain conditions. An attacker could possibly use this issue to bypass authentication. (CVE-2026-27856) It was discovered that Dovecot incorrectly handled certain IMAP login requests. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-27857) It was discovered that Dovecot incorrectly handled certain specially crafted messages. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-27858) It was discovered that Dovecot incorrectly handled certain specially crafted mail messages. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-27859) It was discovered that Dovecot incorrectly handles file paths. A attacker could possibly use this issue to perform a path traversal and obtain or modify arbitrary files. This issue only affected Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-0394)

Recommended actions per Ubuntu release

StackPatch playbook auto-generated per release codename and per affected package.

Ubuntu jammy

dovecot→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-auth-lua→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-auth-lua
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-core→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-core
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-dev→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-dev
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-gssapi→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-gssapi
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-imapd→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-imapd
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-ldap→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-ldap
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-lmtpd→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-lmtpd
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-lucene→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-lucene
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-managesieved→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-managesieved
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-mysql→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-mysql
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-pgsql→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-pgsql
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-pop3d→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-pop3d
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-sieve→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-sieve
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-solr→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-solr
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-sqlite→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-sqlite
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-submissiond→1:2.3.16+dfsg1-3ubuntu2.8apt_upgrade
Standard apt upgrade. Install 1:2.3.16+dfsg1-3ubuntu2.8 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-submissiond
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu noble

dovecot→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-auth-lua→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-auth-lua
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-core→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-core
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-dev→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-dev
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-gssapi→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-gssapi
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-imapd→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-imapd
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-ldap→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-ldap
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-lmtpd→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-lmtpd
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-managesieved→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-managesieved
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-mysql→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-mysql
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-pgsql→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-pgsql
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-pop3d→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-pop3d
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-sieve→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-sieve
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-solr→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-solr
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-sqlite→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-sqlite
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
dovecot-submissiond→1:2.3.21+dfsg1-2ubuntu6.4apt_upgrade
Standard apt upgrade. Install 1:2.3.21+dfsg1-2ubuntu6.4 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y dovecot-submissiond
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Are YOU affected by USN-8136-2?

5-second check on your actual server. Reads /etc/os-release, uname -r, and dpkg-query; matches against the live USN + Debian Security Tracker feeds; tells you whether USN-8136-2 (and any other live CVE) applies. Anonymous, no signup.

curl https://mindsparkstack.com/scan.sh | bash

Form-based quickscan Read the bash source first

References

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