CVE-2026-27858

HIGH

OX Dovecot Pro < 2.3.0, < 3.1.0, < 2.4.0 - Unauthenticated Denial of Service via Managesieve Memory Allocation

Title source: llm
STIX 2.1

Description

Attacker can send a specifically crafted message before authentication that causes managesieve to allocate large amount of memory. Attacker can force managesieve-login to be unavailable by repeatedly crashing the process. Protect access to managesieve protocol, or install fixed version. No publicly available exploits are known.

References (18)

Core 18
Core References

Scores

CVSS v3 7.5
EPSS 0.0079
EPSS Percentile 52.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-400 CWE-770
Status published
Products (5)
dovecot/dovecot < 2.4.3
open-xchange/dovecot < 2.3.22.1
Open-Xchange GmbH/OX Dovecot Pro < 2.3.0
Open-Xchange GmbH/OX Dovecot Pro < 2.4.0
Open-Xchange GmbH/OX Dovecot Pro < 3.1.0
Published Mar 27, 2026
Tracked Since Mar 27, 2026