Quick answers
- Is CVE-2026-33607 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-33607 being exploited in the wild.
- How severe is CVE-2026-33607?
- Medium severity, with a CVSS score of 4.3, published 28 August 2026.
- Which products and versions are affected?
- Open-Xchange Dovecot Pro 2.3.0 to 2.3.22.1, 3.0.0 to 3.0.6, 3.1.0 to 3.1.5.
- Is there a fix for CVE-2026-33607?
- A patch was published on 2026-08-28: Patches available in versions 2.3.22.2, 3.0.7, and 3.1.6+ Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-33607 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-33607?
- Check whether you run Open-Xchange Dovecot Pro at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is a CPU exhaustion / denial-of-service flaw in Dovecot's IMAP LIST command handler. An attacker with valid IMAP credentials can issue specially crafted LIST commands that trigger expensive processing, causing CPU consumption and service degradation or denial of service. The attack requires authentication but is network-reachable via the IMAP protocol. Patches are available in Dovecot versions 2.3.22.2, 3.0.7, and 3.1.6 or later.
Affected products
- Open-Xchange Dovecot Pro 2.3.0 to 2.3.22.1, 3.0.0 to 3.0.6, 3.1.0 to 3.1.5
Timeline
- 2026-08-28: disclosed
- 2026-08-28: patched: Patches available in versions 2.3.22.2, 3.0.7, and 3.1.6+