Quick answers
- Is CVE-2026-40204 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-40204 being exploited in the wild.
- How severe is CVE-2026-40204?
- Low severity, with a CVSS score of 3.1, published 28 August 2026.
- Which products and versions are affected?
- Open-Xchange Dovecot Pro 2.3.0-2.3.22.1, 3.0.0-3.0.6, 3.1.0-3.1.5.
- Is there a fix for CVE-2026-40204?
- A patch was published on 2026-08-28: Patches available in versions 2.3.22.2, 3.0.7, 3.1.6 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-40204 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-40204?
- 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
This is a critical authentication bypass vulnerability in OX Dovecot Pro's authentication mechanism. The vulnerability affects multiple version series (2.3.x, 3.0.x, 3.1.x) and allows unauthenticated network attackers to bypass security controls and gain unauthorized access to user mailboxes. The flaw requires no special privileges or user interaction. Affected versions are 2.3.0 through 2.3.22.1, 3.0.0 through 3.0.6, and 3.1.0 through 3.1.5. Patches are available: update to 2.3.22.2, 3.0.7, or 3.1.6 or later.
Affected products
- Open-Xchange Dovecot Pro 2.3.0-2.3.22.1, 3.0.0-3.0.6, 3.1.0-3.1.5
Timeline
- 2026-08-28: disclosed: Public release of security advisory OXDC-ADV-2026-0003
- 2026-08-28: patched: Patches available in versions 2.3.22.2, 3.0.7, 3.1.6