Apache Airflow SFTP EUVD-2026-102523

Exploitation requires three concrete conditions drawn from the description: (1) the affected connection must run through the SFTP provider's deferrable code paths - specifically SFTPTrigger, SFTPHookAsync, or SFTPClientPool, i.e. an SFTP sensor or operator executed in deferrable mode; (2) the connection must rely on the insecure default where the no_host_key_check extra is left unset/true, with no host_key supplied and no matching entry in known_hosts (deployments that set no_host_key_check=false, supply a host_key, or add the server to known_hosts are not exploitable); and (3) the attacker must occupy a machine-in-the-middle network position between the Airflow triggerer and the SFTP server. The MITM prerequisite is the primary limiting factor - exploitation is not possible by a remote attacker lacking network-path control - which meaningfully reduces realistic risk compared with a direct remote flaw.

No CVSS score, EPSS probability, or SSVC decision data is provided in the input, so quantitative exploitation signals are entirely absent and cannot be compared. Exploitation status is 'no public exploit identified at time of analysis' - this CVE is not in CISA KEV and no POC is referenced. The core risk is a man-in-the-middle (MITM) weakness (CWE-322): the SFTP provider's deferrable code paths (SFTPTrigger, SFTPHookAsync, SFTPClientPool) shipped with SSH host-key verification disabled by default (no_host_key_check defaulting to true), meaning the triggerer never authenticates the remote SFTP server. Realistically this is a conditional, position-dependent flaw rather than a mass-exploitable one: an attacker must already hold a network MITM vantage point between the Airflow triggerer and the SFTP server, which substantially limits opportunistic exploitation and points toward targeted/insider or compromised-network scenarios rather than widespread internet-scale attacks. Impact is meaningful where the condition is met - credentials and transferred data can be captured or manipulated - so for environments running SFTP sensors/operators in deferrable mode over untrusted network segments this warrants prompt patching, but it is not a drop-everything internet-facing RCE. Note the dependency relationship: this is explicitly a separate defect from CVE-2026-94134 (synchronous SSH hook default), and the single release apache-airflow-providers-sftp 7.0.0 fixes both - teams who patched only one issue remain exposed to the other.

An Airflow deployment runs an SFTP sensor or operator in deferrable mode, and the connection leaves no_host_key_check at its insecure default. An attacker positioned on the network path between the triggerer and the SFTP server (e.g. via ARP spoofing, rogue gateway, or DNS redirection) presents a forged host key, which the triggerer accepts without verification, allowing the attacker to impersonate the server and harvest the SFTP credentials and file data during the exchange. No public exploit code is referenced, and success depends on the attacker first achieving the MITM position.