Quick answers
- Is CVE-2026-42392 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-42392 being exploited in the wild.
- How severe is CVE-2026-42392?
- 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-2026-42392?
- A patch was published on 2026-08-28: Patches released for 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-2026-42392 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-42392?
- 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 an information disclosure flaw in the IMAP URLFETCH implementation. An attacker with valid IMAP credentials can craft an invalid URLFETCH command that triggers a code path where uninitialized memory is included in the error response sent back to the client. This is a classic use-after-free or buffer overread style memory disclosure. The attack requires valid authentication credentials and network access to the IMAP service. The impact is limited to information disclosure; no code execution or privilege escalation is possible. Patches are available in 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: Public disclosure of CVE-2026-42392
- 2026-08-28: patched: Patches released for versions 2.3.22.2, 3.0.7, and 3.1.6