CVE-2026-52687

MEDIUMCVSS 6.5/10EPSS 0.32%

Last modified

CVE-2026-52687 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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. EPSS estimates a 0.32% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability
0.32%

24.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
Open-Xchange GmbHOX Dovecot Pro>= 2.3.11, < 2.3.22.2; >= 3.0.0, < 3.0.7; >= 3.1.0, < 3.1.6
Open-Xchange GmbHOX Dovecot CE>= 2.3.11, < 2.4.5

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is 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. 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.
How severe is CVE-2026-52687?
CVE-2026-52687 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.32% probability of exploitation in the next 30 days.
How do I fix CVE-2026-52687?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

Are you affected by CVE-2026-52687?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST