CVE-2026-27859
Fixed in a distro release EPSS <1%CVSS 5.3
A mail message containing excessive amount of RFC 2231 MIME parameters causes LMTP to use too much CPU. A suitably formatted mail message causes mail delivery process to consume large amounts of CPU time. Use MTA capabilities to limit RFC 2231 MIME parameters in mail messages, or upgrade to fixed version where the processing is limited. No publicly available exploits are known.
Products: Open-Xchange GmbH OX Dovecot Pro
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Alpine 3.23 | dovecot | 2.4.3-r0 |
| Alpine 3.24 | dovecot | 2.4.3-r0 |
| 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 |
| 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 16.04 LTS | dovecot | no fix |
| Ubuntu 18.04 LTS | dovecot | no fix |
| 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 |
| Ubuntu Pro 14.04 LTS | dovecot | no fix |
| openSUSE Leap 16.0 | dovecot24 | 2.4.3-160000.1.1 |
| openSUSE Tumbleweed | dovecot24 | 2.4.3-1.1 |