CVE-2026-93994: CWE-304 Missing critical step in authentication in Apache Software Foundation Apache MINA SSHD
Apache MINA SSHD versions before 2.20.0 and between 3.0.0-M1 and 3.0.0-M5 have a vulnerability where the server does not enforce that two required public keys for multi-authentication are distinct. This allows an attacker to bypass the intended multi-key authentication by presenting the same key twice. The issue is fixed in versions 2.20.0 and 3.0.0-M6.
AI Analysis
Technical Summary
Apache MINA SSHD is a Java library for SSH client and server implementations. When configured to require multiple public key authentications (e.g., two distinct keys), versions up to 2.19.0 and 3.0.0-M1 through 3.0.0-M5 fail to verify that the two keys are different. Consequently, an attacker can authenticate by presenting the same public key twice, bypassing the multi-authentication requirement. This is classified as CWE-304 (Missing Critical Step in Authentication).
Potential Impact
Successful exploitation allows an attacker to bypass the multi-authentication requirement by using a single public key twice, potentially granting unauthorized access. The vulnerability impacts confidentiality and integrity but does not affect availability. The CVSS v3.1 score is 8.1 (High), reflecting network attack vector, low attack complexity, privileges required, no user interaction, and high impact on confidentiality and integrity.
Mitigation Recommendations
Users should upgrade Apache MINA SSHD to version 2.20.0 or 3.0.0-M6 or later, where this authentication bypass vulnerability is fixed. No other mitigations are indicated by the vendor advisory.
CVE-2026-93994: CWE-304 Missing critical step in authentication in Apache Software Foundation Apache MINA SSHD
Description
Apache MINA SSHD versions before 2.20.0 and between 3.0.0-M1 and 3.0.0-M5 have a vulnerability where the server does not enforce that two required public keys for multi-authentication are distinct. This allows an attacker to bypass the intended multi-key authentication by presenting the same key twice. The issue is fixed in versions 2.20.0 and 3.0.0-M6.
CVSS v3.1
Score 8.1high
Affected software
Apache Software Foundation
Apache MINA SSHD
pkg:maven/Apache Software Foundation/org.apache.sshd:sshd-coreRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Apache MINA SSHD is a Java library for SSH client and server implementations. When configured to require multiple public key authentications (e.g., two distinct keys), versions up to 2.19.0 and 3.0.0-M1 through 3.0.0-M5 fail to verify that the two keys are different. Consequently, an attacker can authenticate by presenting the same public key twice, bypassing the multi-authentication requirement. This is classified as CWE-304 (Missing Critical Step in Authentication).
Potential Impact
Successful exploitation allows an attacker to bypass the multi-authentication requirement by using a single public key twice, potentially granting unauthorized access. The vulnerability impacts confidentiality and integrity but does not affect availability. The CVSS v3.1 score is 8.1 (High), reflecting network attack vector, low attack complexity, privileges required, no user interaction, and high impact on confidentiality and integrity.
Mitigation Recommendations
Users should upgrade Apache MINA SSHD to version 2.20.0 or 3.0.0-M6 or later, where this authentication bypass vulnerability is fixed. No other mitigations are indicated by the vendor advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- apache
- Date Reserved
- 2026-09-19T12:21:52.758Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6abce0dc0df196e1a9de7073
Added to database: 09/30/2026, 10:13:48 UTC
Last enriched: 09/30/2026, 10:27:16 UTC
Last updated: 09/30/2026, 10:44:21 UTC
Views: 5
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