The Galaxy FDS Android SDK by Xiaomi, up to version 3.0.8, contains a severe security vulnerability identified as CVE-2026-26214, classified under CWE-297 (Improper Validation of Certificate with Host Mismatch). The root cause is the SDK's default configuration of the Apache HttpClient to use SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER, which disables hostname verification during TLS handshake. This means that while the TLS certificate itself is validated, the hostname presented by the server is not checked against the certificate's subject or SAN fields. Consequently, an attacker capable of performing a man-in-the-middle (MitM) attack can present a valid TLS certificate for any hostname, intercepting and potentially modifying all HTTPS traffic between the client application and Xiaomi's FDS cloud storage endpoints. Since HTTPS is enabled by default in the SDK's FDSClientConfiguration, all applications using the SDK without custom configuration are vulnerable. The vulnerability allows attackers to capture sensitive data such as authentication tokens, file contents, and API responses, compromising confidentiality and integrity. The SDK is open source but has reached end-of-life, meaning no official patches or updates will be provided. The CVSS 4.0 vector indicates network attack vector, high attack complexity, no privileges or user interaction required, and high impact on confidentiality and integrity, confirming the critical nature of this flaw. No known exploits are currently reported in the wild, but the ease of exploitation and impact make it a significant threat.

For European organizations, this vulnerability poses a critical risk especially for those developing or deploying Android applications that integrate Xiaomi's Galaxy FDS SDK for cloud storage functionalities. The potential interception and manipulation of data can lead to unauthorized disclosure of sensitive information, including user credentials and proprietary files, resulting in data breaches and loss of trust. Integrity of data stored or retrieved via the SDK can be compromised, potentially affecting business operations and compliance with data protection regulations such as GDPR. The lack of hostname verification undermines the fundamental security guarantees of TLS, exposing organizations to espionage, data tampering, and further lateral attacks within their networks. Given the SDK's end-of-life status, organizations cannot rely on vendor patches, increasing the urgency to remediate or replace the SDK. This threat is particularly impactful for sectors handling sensitive personal or corporate data, including finance, healthcare, and government services within Europe.

1. Immediate audit of all Android applications to identify usage of the Galaxy FDS Android SDK, especially versions 3.0.8 and earlier. 2. Remove or replace the vulnerable SDK with a secure alternative that properly validates TLS hostnames. 3. If removal is not immediately feasible, implement custom hostname verification logic in the application to override the default insecure behavior. 4. Employ network-level protections such as enforcing TLS interception detection, using VPNs, or network segmentation to reduce the risk of MitM attacks. 5. Monitor network traffic for unusual patterns indicative of interception or tampering. 6. Educate development teams about secure TLS practices and the risks of disabling hostname verification. 7. For applications already deployed, consider issuing updates or patches that address the vulnerability or disable the affected SDK features. 8. Engage in threat intelligence sharing within industry groups to stay informed about any emerging exploits targeting this vulnerability. 9. Review and strengthen overall mobile application security policies to prevent similar issues in third-party SDKs.