CVE-2026-42395: Uncontrolled Resource Consumption in Open-Xchange GmbH OX Dovecot Pro
Description
CVE-2026-42395 is a medium severity vulnerability in Open-Xchange GmbH's OX Dovecot Pro. It involves uncontrolled resource consumption caused by a trusted proxy sending forwarding information containing a NUL byte, which crashes the login process on subsequent login attempts. This can lead to degradation or denial of service for logins. Systems not configured with trusted proxies are not affected.
CVSS v3.1
Score 4.3medium
Affected software
Open-Xchange GmbH
OX Dovecot Pro
Open-Xchange GmbH
OX Dovecot CE
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability occurs when a host configured as a trusted proxy sends forwarding information containing a NUL byte. This input causes the login process in OX Dovecot Pro to crash on the next login attempt, terminating the process and potentially causing denial of service. The issue only affects deployments that configure trusted proxies. No public exploits are known, and no official remediation or patch information is provided in the available data.
Potential Impact
The impact is limited to denial of service or degradation of login functionality due to the login process crashing when processing malicious forwarding information from a trusted proxy. There is no confidentiality or integrity impact reported. Systems without trusted proxy configurations are not vulnerable.
Mitigation Recommendations
Restrict the list of trusted proxy networks to hosts fully under your control to prevent untrusted sources from sending malicious forwarding information. Update to a non-vulnerable version when available. Since no official patch or remediation level is provided, check the vendor advisory for updates. No public exploits are known, so immediate exploitation risk appears low.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- OX
- Date Reserved
- 2026-04-27T08:53:58.839Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a916f8dacd9273b49cf9250
Added to database: 08/28/2026, 11:22:53 UTC
Last enriched: 09/10/2026, 02:38:51 UTC
Last updated: 10/10/2026, 18:48:19 UTC
Views: 50
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