VulnerabilityPublished 12 Nov 2026

CVE-2026-126641: Red Hat Ansible Automation Platform 2 · Key Exchange Without Entity Authentication

Affects Red Hat Ansible Automation Platform 2Source CVE Database V5

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Not known to be exploited · CVSS 6.5 Medium.

Data as of 12 Nov 2026, 11:06 UTC

CVSS 3.1 base score

6.5Medium

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (redhat)	CVSS 3.1	6.5

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: Low
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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on 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 12 Nov 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 11 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.

What to do

Affected software

Product	Affected	Fixed in
Red Hat Ansible Automation Platform 2ansible-automation-platform-26/ee-supported-rhel9	Affected–	Fixed in–
Red Hat Ansible Automation Platform 2ansible-automation-platform-27/ee-supported-rhel9	Affected–	Fixed in–
Red Hat Ansible Automation Platform 2python3.11-ansible-pylibssh	Affected–	Fixed in–
Red Hat Ansible Automation Platform 2python3.12-ansible-pylibssh	Affected–	Fixed in–
Red Hat Ansible Automation Platform 2python3x-ansible-pylibssh	Affected–	Fixed in–
Red Hat Ansible Automation Platform 2python-ansible-pylibssh	Affected–	Fixed in–

AI-suggested

Do not enable host_key_auto_add in the ansible.netcommon libssh connection plugin or AutoAddPolicy in ansible-pylibssh. Keep host_key_checking enabled and pre-populate known_hosts with verified host keys to ensure that changed keys cause connection failures. Since default configurations are not affected and non-interactive runs fail closed, maintaining default settings effectively mitigates this vulnerability.

Description

CVE-2026-126641 is a vulnerability in Red Hat Ansible Automation Platform 2 involving host key verification when trust-on-first-use is enabled. Specifically, if a host key changes for a host already in known_hosts, the new key is accepted without warning, allowing a man-in-the-middle attacker to impersonate the host and potentially capture credentials. Default configurations with host key checking enabled and trust-on-first-use disabled are not affected. Exploitation requires a non-default configuration and an attacker positioned to intercept connections.

Impact

If exploited under the required conditions, an attacker can impersonate a trusted host by presenting a changed SSH host key that is accepted without warning. This can lead to disclosure of connection credentials and unauthorized execution of playbooks on the attacker's host. The vulnerability impacts confidentiality with high severity and integrity with low severity, but does not affect availability. Default configurations are not vulnerable, and exploitation complexity is high due to required attacker positioning and non-default settings.

Summary

This vulnerability arises from a flaw in ansible-pylibssh and the ansible.netcommon libssh connection plugin where the host key verification process incorrectly accepts changed host keys when trust-on-first-use is enabled (host_key_auto_add or AutoAddPolicy). The verification method treats changed keys as if they were unknown, adding the new key and continuing the connection instead of aborting. This behavior allows the Ansible controller to authenticate to a substitute host controlled by an attacker, run playbooks there, and append the attacker's key to known_hosts, risking credential disclosure via a man-in-the-middle attack. Default settings with host_key_checking enabled and trust-on-first-use disabled cause non-interactive runs to fail closed, mitigating the risk. The flaw requires explicit enabling of trust-on-first-use and an attacker capable of intercepting the connection.

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What to do

Affected software

Description

AI analysisMachine-generated, updated 12 Nov 2026, 11:06 UTC

Technical details

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