Description
In Dovecot before 2.3.10.1, a crafted SMTP/LMTP message triggers an unauthenticated use-after-free bug in submission-login, submission, or lmtp, and can lead to a crash under circumstances involving many newlines after a command.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | dovecot | 1:2.3.10.1+dfsg1-1 | — |
| Debian 13 | dovecot | 1:2.3.10.1+dfsg1-1 | — |
| Debian 12 | dovecot | 1:2.3.10.1+dfsg1-1 | — |
| Debian 10 | dovecot | 1:2.3.4.1-5+deb10u2 | DSA-4690-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | dovecot | 1:2.3.7.2-1ubuntu3.1 | USN-4361-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | dovecot +4 | 1:2.3.8-4.el8 | RHSA-2020:4763 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | dovecot +1 | 1:2.3.8-4.el8 | ALSA-2020:4763 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP1 | dovecot23 | 2.3.10-11.1 | SUSE-SU-2020:1380-1 |
| SLES 15 | dovecot23 | 2.3.10-4.22.1 | SUSE-SU-2020:1379-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 | dovecot23 | 2.3.10-4.22.1 | SUSE-SU-2020:1379-1 |
| SLE HPC 15 | dovecot23 | 2.3.10-4.22.1 | SUSE-SU-2020:1379-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | dovecot23 | 2.3.16-1.6 | openSUSE-SU-2024:10726-1 |
| openSUSE Tumbleweed | dovecot24 | 2.4.0-1.1 | openSUSE-SU-2025:14715-1 |
| openSUSE Leap 15.1 | dovecot23 | 2.3.10-lp151.2.9.1 | openSUSE-SU-2020:0720-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.23 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.22 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.21 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.20 | dovecot | 2.3.10.1-r0 | — |
Show 12 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.18 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.17 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.16 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.15 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.14 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.13 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.12 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.11 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.10 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.9 | dovecot | 2.3.10.1-r0 | — |
| Alpine v3.8 | dovecot | 2.3.10.1-r0 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | dovecot +4 | 1:2.3.8-4.el8 | ELSA-2020-4763 |
Advisories 11
- ALSA-2020:4763 Moderate: dovecot security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2020:4763 Red Hat Security Advisory: dovecot security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-4361-1 dovecot vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4690-1 dovecot - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2020:1379-1 Security update for dovecot23 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:0720-1 Security update for dovecot23 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14715-1 dovecot24-2.4.0-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:1380-1 Security update for dovecot23 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10726-1 dovecot23-2.3.16-1.6 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- WID-SEC-2025-0236 Dovecot: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Feb 2, 2025
- ELSA-2020-4763 Moderate: dovecot security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 10, 2020
References
- https://dovecot.org/security
- https://www.openwall.com/lists/oss-security/2020/05/18/1
- [oss-security] 20200518 Multiple vulnerabilities in Dovecot IMAP server mailing-list
- USN-4361-1 vendor-advisory
- 20200519 Multiple vulnerabilities in Dovecot IMAP server mailing-list
- http://packetstormsecurity.com/files/157771/Open-Xchange-Dovecot-2.3.10-Null-Pointer-Dereference-Denial-Of-Service.html
- DSA-4690 vendor-advisory
- FEDORA-2020-1dee17d880 vendor-advisory
- openSUSE-SU-2020:0720 vendor-advisory
- FEDORA-2020-b60344c987 vendor-advisory