CVE-2026-42395

Summary

A host listed as a trusted proxy can send forwarding information containing a NUL byte, which crashes the login process on the following login attempt. The login process is terminated, which can cause degradation or denial of service for logins. Deployments that do not configure trusted proxies are not affected. Restrict the list of trusted proxy networks to hosts that are fully under your control. Update to non-vulnerable version. No publicly available exploits are known.

Affected Software

VendorProductVersion RangeStatus
Open-Xchange GmbHOX Dovecot Pro2.3.0 < 2.3.22.2affected
Open-Xchange GmbHOX Dovecot Pro3.0.0 < 3.0.7affected
Open-Xchange GmbHOX Dovecot Pro3.1.0 < 3.1.6affected
Open-Xchange GmbHOX Dovecot CE2.3.0 < 2.4.5affected

Weaknesses

  • CWE-400: Uncontrolled Resource Consumption

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References