External risk intelligence

Apache MINA SSHD Authentication Bypass in sshd-ldap.

CVE advisorySeverity: CRITICAL (CVSS 9.1)

CVE-2026-94052

The vulnerability affects Apache MINA SSHD, a library used to build SSH servers. SSH services are commonly deployed as network-facing remote access or management gateways. While the specific LDAP authentication component is optional, its inclusion in an SSH server typically facilitates network-accessible authentication for remote connectivity.

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This advisory addresses a critical vulnerability in the Apache MINA SSHD library, specifically within its optional `sshd-ldap` component. If this component is used for password authentication via LDAP, a flaw could allow bypass of authentication checks. This situation warrants attention to confirm if your organization utilizes this specific, optional configuration for SSH access.

Authentication bypassed for specific SSH configurations.
Critical flaw affects network access authentication.
Confirm use of optional LDAP SSH authentication.

Attack Path

How an attacker could exploit the issue

An attacker could reach an SSH server that uses a specific LDAP password authentication method. By sending specially crafted requests, an attacker might bypass the standard authentication checks, potentially gaining unauthorized access.

Requires an SSH server using LDAP password authentication.
Bypasses authentication checks during login.
Could lead to unauthorized access.

Live Threat

Current exploitation, exposure, and threat context

When supported by the advisory, the `LdapPasswordAuthenticator` component within Apache MINA SSHD could bypass authentication checks. This affects SSH servers configured to use this specific LDAP authentication method for password-based logins.

Affects SSH server authentication.
Bypasses authentication checks for LDAP.
Unauthorized access to systems.

Operational Fix

Recommended remediation, mitigation, and detection steps

Platform or application teams managing SSH servers that utilize the optional `sshd-ldap` component for password authentication are responsible for addressing this vulnerability. The first practical step is to identify all instances of Apache MINA SSHD configured with `LdapPasswordAuthenticator`, confirm their network exposure and business criticality, and then coordinate with the relevant owner to plan remediation during the next maintenance window.

Identify accountable platform or application owners.
Verify LDAP authenticator configuration and exposure.
Plan remediation based on identified risk.

Supplementary metadata

CVSS vector

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Frequently asked questions

What is Apache MINA SSHD and the sshd-ldap component?

Apache MINA SSHD is a Java library developers use to build SSH client or server applications. The sshd-ldap component is an optional module that allows these SSH servers to verify user passwords against an external LDAP directory service instead of local system files.

How does the CVE-2026-94052 authentication bypass work?

This vulnerability is classified as CWE-304, which refers to a missing check in the authentication process. In this specific case, the flaw exists within the LdapPasswordAuthenticator class, allowing an attacker to bypass the intended verification steps and gain access without providing valid credentials.

When is an SSH server vulnerable to this bug?

An SSH server is only vulnerable if it actively uses the optional sshd-ldap component and is explicitly configured to use the LdapPasswordAuthenticator. If your server uses standard password authentication or public key mechanisms managed by the core sshd library, it is not affected.

Why should I care about this vulnerability?

According to Halo Surface Signal, this vulnerability is classified as external because it impacts SSH services, which are frequently deployed as network-accessible gateways. If your environment uses this specific LDAP configuration for remote connectivity, the risk of unauthorized access is elevated.

How do I address CVE-2026-94052 in my environment?

First, locate all applications using the Apache MINA SSHD library to determine if the optional LDAP authenticator is enabled. If you identify an affected configuration, coordinate with your technical teams to update the library to version 2.20.0 or 3.0.0-M6, which contain the necessary security fixes.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.