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)
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.004 (35.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 35.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.001
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.