SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-52687

An attacker that has valid credentials can select a compression algorithm for the IMAP connection whose decompression state requires a large amount of memory, and open several such connections.

MEDIUM 6.5EPSS 0.32%

Does this matter?

Lower severity and a low EPSS score (0.32%). Track it; it rarely justifies an emergency change on its own.

Description

An attacker that has valid credentials can select a compression algorithm for the IMAP connection whose decompression state requires a large amount of memory, and open several such connections. The memory limit of the process is reached with only a few connections, terminating the process and all connections it handles, which can cause degradation or denial of service for IMAP. Disable IMAP compression. Alternatively limit the number of connections handled by a single imap-login process, though this has a performance impact. Update to non-vulnerable version. No publicly available exploits are known.

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
0.32% probability · 25th percentile
CISA KEV
Not listed
Weakness
CWE-400
Source
security@open-xchange.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.