CVE-2026-42395 — MEDIUM (4.3)

Vulnerability Description

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.

CVSS Score

4.3

MEDIUM

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector

ADJACENT_NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

NONE

Availability

LOW

Related Weaknesses (CWE)

CWE-400

References

https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxd

FAQ

What is CVE-2026-42395?

CVE-2026-42395 is a vulnerability with a CVSS score of 4.3 (MEDIUM). 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...

How severe is CVE-2026-42395?

CVE-2026-42395 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-42395?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.