Description
An attacker that has valid credentials can submit a Sieve script containing an extreme numeric literal, which causes an out-of-bounds write when the ManageSieve service compiles the script. This causes memory corruption and an observed crash of the ManageSieve process, resulting in denial of service for script management. This might be able to be used for remote code execution. Disable the ManageSieve service if users do not need remote Sieve script management. Update to non-vulnerable version. No publicly available exploits are known.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Open-Xchange | OX Dovecot Pro | 2.3.0 – < 2.3.22.2, 3.0.0 – < 3.0.7, 3.1.0 – < 3.1.6 | 2.3.22.2 |
| Open-Xchange | OX Dovecot CE | 2.3.0 – < 2.4.5 | 2.4.5 |
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 | 1:2.4.5+dfsg1-1 | — |
| Debian 13 | dovecot | 1:2.4.1+dfsg1-6+deb13u7 | — |
| Debian 12 | dovecot | 1:2.3.19.1+dfsg1-2.1+deb12u7 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | dovecot | No fix yet | — |
| Ubuntu 24.04 LTS | dovecot | No fix yet | — |
| Ubuntu 22.04 LTS | dovecot | No fix yet | — |
| Ubuntu 20.04 LTS | dovecot | No fix yet | — |
| Ubuntu 18.04 LTS | dovecot | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | dovecot | No fix yet | — |
| Ubuntu Pro 14.04 LTS | dovecot | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | dovecot24 | 2.4.4-160000.2.1 | SUSE-SU-2026:23595-1 |
| SLES 16.0 | dovecot24 | 2.4.4-160000.2.1 | SUSE-SU-2026:23595-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | dovecot24 | 2.4.4-160000.2.1 | openSUSE-SU-2026:21720-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | dovecot | No fix yet | — |
Advisories 3
- WID-SEC-2026-3076 Dovecot: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- SUSE-SU-2026:23595-1 Security update for dovecot24 SUSE / openSUSE Security Updates · Sep 29, 2026
- openSUSE-SU-2026:21720-1 Security update for dovecot24 SUSE / openSUSE Security Updates · Sep 2, 2026