VulnerabilityPublished 30 Sep 2026

CVE-2026-93994: Apache MINA SSHD · Missing Critical Step in Authentication

Affects Apache MINA SSHDSource CVE Database V5

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Not known to be exploited · CVSS 8.1 High : upgrade to 3.0.0-M6 or 2.20.0 soon.

Data as of 12 Nov 2026, 23:25 UTC

CVSS 3.1 base score

8.1High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.0.0-M6, 2.20.0

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 30 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-qc4p-9828-mv83

What to do

Upgrade Apache to 3.0.0-M6 or 2.20.0.

Affected software

Product	Affected	Fixed in
Apache Software FoundationApache MINA SSHD	Affected >=3.0.0-M1 <3.0.0-M6	Fixed in 3.0.0-M6
Apache Software FoundationApache MINA SSHD	Affected <2.20.0	Fixed in 2.20.0
MavenApache Software Foundation/org.apache.sshd:sshd-core`pkg:maven/Apache Software Foundation/org.apache.sshd:sshd-core`Other threats	Affected <2.20.0 >=3.0.0-M1 <3.0.0-M6	Fixed in 2.20.0 3.0.0-M6

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

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.

Description

Apache MINA SSHD is a Java library for client-side and server-side SSH. SSH servers can be configured to require multi-authentication schemes, for instance two different public keys, not just one. In OpenSSH, this would be done by setting in sshd_config AuthenticationMethods "publickey,publickey". Apache MINA SSHD provides an equivalent configuration mechanism. In Apache MINA SSHD versions up to 2.19.0 and 3.0.0-M1 to 3.0.0-M5 the server code in component sshd-core does not enforce that the two public keys presented are different. A user can thus successfully authenticate with only one of the two key pairs required by presenting this single key twice. This is a partial authentication bypass. Users are recommended to upgrade to version 2.20.0 or 3.0.0-M6, which fix this issue.

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.

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).

CWE-304Missing Critical Step in Authentication (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product implements an authentication technique, but it skips a step that weakens the technique.
OWASP Cheat Sheets
Choosing and Using Security Questions (opens in a new tab)
Forgot Password (opens in a new tab)
Authentication (opens in a new tab)
Transport Layer Protection (opens in a new tab)
TLS Cipher String (opens in a new tab)
OWASP ASVS 4.0.3
V2.5.5 (opens in a new tab)
V2.2.2 (opens in a new tab)
V2.8.5 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Sep 2026, 10:27 UTC

WeaknessesCWE-304

Technical details

References

Community reviews

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