Resource exhaustion in Open-Xchange Gmbh Ox Dovecot Pro

CVE-2026-27852

An attacker that can send mail to a user can craft a message whose headers contain a very large number of email addresses or MIME parameters, which causes excessive memory usage when the message is later parsed. The message is still delivered, but reading it over IMAP can exhaust the memory limit of the process and terminate it, causing denial of service for the affected user. Update to non-vulnerable version. No publicly available exploits are known.

Vulnerability class: DoS (Denial of Service)

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-27852?
CVE-2026-27852 is a high-severity vulnerability in Open-Xchange Gmbh Ox Dovecot Pro, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-08-28.
How severe is CVE-2026-27852?
High severity. CVSS v3 base score is 7.5 out of 10.