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OpenAdvisories
Low · 3.1 CVE-2026-52681 EUVD-2026-67678GHSA-x4gp-83hc-j86g

Sieve CPU resource usage is tracked in the compiled script, so an attacker that has valid credentials can reset the accounting by repeatedl…

Published Aug 28, 2026 · Updated Aug 28, 2026 · Assigned by OX

Description

Sieve CPU resource usage is tracked in the compiled script, so an attacker that has valid credentials can reset the accounting by repeatedly changing the active script. Compiled script files are also not removed when a script is deleted or renamed. The configured Sieve CPU limit can be bypassed, allowing sustained CPU consumption, and the leftover files increase disk consumption. Both can cause degradation of service for mail delivery. Monitor system for abnormal CPU usage and disk consumption. Update to non-vulnerable version. No publicly available exploits are known.

Affected products

VendorProductAffectedFixed
Open-Xchange OX Dovecot Pro 2.3.15 – < 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 2.3.15 – < 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.

ReleasePackageFixed inAdvisory
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 —
ReleasePackageFixed inAdvisory
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)
ReleasePackageFixed inAdvisory
Ubuntu 16.04 LTS dovecot No fix yet —
Ubuntu Pro 14.04 LTS dovecot No fix yet —
ReleasePackageFixed inAdvisory
SLES 15 SP7 dovecot23 2.3.21.1-150200.76.1 SUSE-SU-2026:4139-1
SLES 15 SP6 dovecot23 2.3.21.1-150200.76.1 SUSE-SU-2026:4139-1
SLES 15 SP5 dovecot23 2.3.21.1-150200.76.1 SUSE-SU-2026:4139-1
SLES 15 SP4 dovecot23 2.3.21.1-150200.76.1 SUSE-SU-2026:4139-1
Show 7 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 dovecot24 2.4.4-160000.2.1 SUSE-SU-2026:23595-1
SLES for SAP 15 SP6 dovecot23 2.3.21.1-150200.76.1 SUSE-SU-2026:4139-1
SLES for SAP 15 SP5 dovecot23 2.3.21.1-150200.76.1 SUSE-SU-2026:4139-1
SLES for SAP 15 SP4 dovecot23 2.3.21.1-150200.76.1 SUSE-SU-2026:4139-1
SLES 16.0 dovecot24 2.4.4-160000.2.1 SUSE-SU-2026:23595-1
SLE HPC 15 SP5 dovecot23 2.3.21.1-150200.76.1 SUSE-SU-2026:4139-1
SLE HPC 15 SP4 dovecot23 2.3.21.1-150200.76.1 SUSE-SU-2026:4139-1
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed dovecot24 2.4.5-1.1 openSUSE-SU-2026:11629-1
openSUSE Leap 16.0 dovecot24 2.4.4-160000.2.1 openSUSE-SU-2026:21720-1
ReleasePackageFixed inAdvisory
Alpine v3.24 dovecot 2.4.5-r0 —
Alpine v3.23 dovecot 2.4.5-r0 —

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 dovecot No fix yet —

Advisories 5

References