Is there a public exploit for CVE-2026-126641?

No public exploit for CVE-2026-126641 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-126641?

CVE-2026-126641 scores CVSS 6.5 (v3.1), rated medium.

6.5 Medium

A host key verification flaw was found in ansible-pylibssh and in the ansible.netcommon libssh connection plugin.

CVE-2026-126641

A host key verification flaw was found in ansible-pylibssh and in the ansible.netcommon libssh connection plugin. When trust-on-first-use is enabled (hostkeyautoadd on the libssh connection plugin, or AutoAddPolicy in ansible-pylibssh), a host that is already present in knownhosts but now presents a different key is accepted without warning. The pylibssh Session.verifyknownhost() method passes the SSHKNOWNHOSTSCHANGED and SSHKNOWNHOSTSOTHER states to the same missinghostkey() policy hook used for unknown hosts, and the bundled AutoAddPolicy/RejectPolicy classes (as well as ansible.netcommon's MyAddPolicy, which is modeled on paramiko's AutoAddPolicy) therefore add the changed key and continue the connection rather than aborting as paramiko's BadHostKeyException path would. As a result the controller authenticates to the substitute host, runs the play there, and appends the new key to knownhosts, which can disclose connection credentials to an attacker performing a machine-in-the-middle attack. Default configurations (hostkeychecking enabled, hostkeyautoadd unset) are not affected; non-interactive runs fail closed.

Assessment

CVSS: 6.5 (v3.1)
Severity: Medium
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 12 November 2026
Last updated: 12 November 2026
Assigner: redhat

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

At the source

EUVD (ENISA)

References

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