CVE-2026-52687
Dovecot IMAP Compression Denial of Service Vulnerability
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.
INFO
Published Date :
Aug. 28, 2026, 12:16 p.m.
Last Modified :
Aug. 28, 2026, 12:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-52687
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 8ce71d90-2354-404b-a86e-bec2cc4e6981 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Disable IMAP compression.
- Limit the number of connections per process.
- Update to a non-vulnerable version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-52687.
| URL | Resource |
|---|---|
| https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-52687 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-52687
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-52687 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-52687 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 28, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-400 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/52xxx/CVE-2026-52687.json">CVE-2026-52687</a> Added Reference https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json