CVE-2026-27856
Fixed in a distro release EPSS <1%CVSS 7.4
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.
Products: Open-Xchange GmbH OX Dovecot Pro, Red Hat Enterprise Linux 7 Extended Lifecycle Support, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Alpine 3.23 | dovecot | 2.4.3-r0 |
| Alpine 3.24 | dovecot | 2.4.3-r0 |
| Amazon Linux 2 | dovecot | 1:2.2.36-6.amzn2.1.3 |
| Amazon Linux 2 | dovecot-devel | 1:2.2.36-6.amzn2.1.3 |
| Amazon Linux 2 | dovecot-mysql | 1:2.2.36-6.amzn2.1.3 |
| Amazon Linux 2 | dovecot-pgsql | 1:2.2.36-6.amzn2.1.3 |
| Amazon Linux 2 | dovecot-pigeonhole | 1:2.2.36-6.amzn2.1.3 |
| Amazon Linux 2023 | dovecot | 1:2.3.20-1.amzn2023.0.3 |
| Amazon Linux 2023 | dovecot-devel | 1:2.3.20-1.amzn2023.0.3 |
| Amazon Linux 2023 | dovecot-mysql | 1:2.3.20-1.amzn2023.0.3 |
| Amazon Linux 2023 | dovecot-pgsql | 1:2.3.20-1.amzn2023.0.3 |
| Amazon Linux 2023 | dovecot-pigeonhole | 1:2.3.20-1.amzn2023.0.3 |
| Debian 12 | dovecot | 1:2.3.19.1+dfsg1-2.1+deb12u2 |
| Debian 13 | dovecot | 1:2.4.1+dfsg1-6+deb13u4 |
| Debian 14 | dovecot | 1:2.4.3+dfsg1-1 |
| Red Hat rhel els 7 | dovecot | 1:2.2.36-8.el7_9.1 |
| Red Hat rhel els 7 | dovecot-debuginfo | 1:2.2.36-8.el7_9.1 |
| Red Hat rhel els 7 | dovecot-devel | 1:2.2.36-8.el7_9.1 |
| Red Hat rhel els 7 | dovecot-mysql | 1:2.2.36-8.el7_9.1 |
| Red Hat rhel els 7 | dovecot-pgsql | 1:2.2.36-8.el7_9.1 |
| Red Hat rhel els 7 | dovecot-pigeonhole | 1:2.2.36-8.el7_9.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | dovecot23 | 2.3.21.1-150200.76.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | dovecot23 | 2.3.21.1-150200.76.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | dovecot23 | 2.3.21.1-150200.76.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | dovecot23 | 2.3.21.1-150200.76.1 |
| SUSE Linux Enterprise Module for Server Applications 15 SP7 | dovecot23 | 2.3.21.1-150200.76.1 |
| SUSE Linux Enterprise Server 15 SP4-LTSS | dovecot23 | 2.3.21.1-150200.76.1 |
| SUSE Linux Enterprise Server 15 SP5-LTSS | dovecot23 | 2.3.21.1-150200.76.1 |
| SUSE Linux Enterprise Server 15 SP6-LTSS | dovecot23 | 2.3.21.1-150200.76.1 |
| SUSE Linux Enterprise Server 16.0 | dovecot24 | 2.4.3-160000.1.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | dovecot23 | 2.3.21.1-150200.76.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | dovecot23 | 2.3.21.1-150200.76.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | dovecot23 | 2.3.21.1-150200.76.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | dovecot24 | 2.4.3-160000.1.1 |
| Ubuntu 20.04 LTS | dovecot | no fix |
| Ubuntu 22.04 LTS | dovecot | 1:2.3.16+dfsg1-3ubuntu2.7 |
| Ubuntu 24.04 LTS | dovecot | 1:2.3.21+dfsg1-2ubuntu6.3 |
| Ubuntu 25.10 | dovecot | 1:2.4.1+dfsg1-5ubuntu4.1 |
| openSUSE Leap 16.0 | dovecot24 | 2.4.3-160000.1.1 |
| openSUSE Tumbleweed | dovecot24 | 2.4.3-1.1 |