CVE-2025-26864 is a high-severity vulnerability affecting Apache IoTDB, an open-source time-series database designed for Internet of Things (IoT) data management. The vulnerability arises from the OpenIdAuthorizer component, which improperly exposes sensitive information to unauthorized actors and inserts sensitive data into log files. Specifically, this is classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor) and CWE-532 (Insertion of Sensitive Information into Log File). The affected versions include Apache IoTDB from 0.10.0 through 1.3.3 and versions from 2.0.1-beta before 2.0.2. The vulnerability allows an attacker to remotely access sensitive information without any authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The impact is limited to confidentiality, with no integrity or availability effects. The vulnerability is exploitable over the network with low complexity, making it a significant risk for deployments of Apache IoTDB that have not applied the patches. The issue is resolved in versions 1.3.4 and 2.0.2. No known exploits are reported in the wild yet, but the high CVSS score of 7.5 reflects the potential severity if exploited. The vulnerability could lead to leakage of sensitive configuration or authentication data, which could facilitate further attacks or unauthorized access to IoTDB-managed data.

For European organizations, the exposure of sensitive information in Apache IoTDB could have serious consequences, especially for industries relying on IoT data such as manufacturing, energy, smart cities, and healthcare. Unauthorized disclosure of sensitive configuration or authentication data could enable attackers to escalate privileges or move laterally within networks, potentially compromising critical infrastructure or sensitive personal data protected under GDPR. The confidentiality breach could lead to regulatory penalties, reputational damage, and operational disruptions. Given the increasing adoption of IoT solutions in Europe, organizations using vulnerable versions of Apache IoTDB are at risk of data leaks that could undermine trust and compliance. The lack of required authentication for exploitation increases the threat surface, making exposed IoTDB instances attractive targets for opportunistic attackers or advanced persistent threats.

European organizations should immediately assess their use of Apache IoTDB and identify any deployments running affected versions (0.10.0 through 1.3.3 and 2.0.1-beta before 2.0.2). The primary mitigation is to upgrade Apache IoTDB to versions 1.3.4 or 2.0.2, which contain the fix for this vulnerability. Additionally, organizations should audit and restrict network access to IoTDB instances, ensuring they are not exposed to untrusted networks or the internet. Implement network segmentation and firewall rules to limit access to trusted users and systems only. Review and sanitize logs to ensure no sensitive information is unnecessarily recorded. Employ monitoring and anomaly detection to identify unusual access patterns to IoTDB services. Finally, incorporate this vulnerability into vulnerability management and patching workflows to prevent future exposure.