CVE-2025-27522 is a vulnerability classified under CWE-502, which involves the deserialization of untrusted data within the Apache InLong project, versions 1.13.0 through 2.1.0. Apache InLong is an open-source data streaming and log collection framework widely used for managing large-scale data pipelines. The vulnerability represents a secondary mining bypass related to a previously disclosed issue, CVE-2024-26579, indicating that it circumvents protections implemented to mitigate that earlier flaw. Deserialization vulnerabilities occur when untrusted input is processed by the application’s deserialization mechanisms, potentially allowing attackers to manipulate the data stream or inject malicious objects. In this case, the vulnerability can be exploited remotely without authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The impact primarily affects confidentiality and integrity, with no direct availability impact reported. The CVSS base score of 6.5 reflects a medium severity level, highlighting a moderate risk. The vulnerability can allow attackers to bypass security controls related to data processing, potentially leading to unauthorized data access or manipulation. The Apache Software Foundation has addressed this issue in version 2.2.0 of Apache InLong and provided a patch (pull request #11732) to remediate the vulnerability. No known exploits have been reported in the wild as of the publication date, but the nature of the vulnerability warrants proactive mitigation. Organizations using affected versions of Apache InLong should upgrade promptly to avoid potential exploitation.

For European organizations, the impact of CVE-2025-27522 can be significant in environments where Apache InLong is deployed for critical data streaming and log aggregation tasks. The vulnerability could allow attackers to bypass secondary mining protections, potentially leading to unauthorized access or manipulation of sensitive data streams. This may compromise data confidentiality and integrity, affecting compliance with data protection regulations such as GDPR. Although availability is not directly impacted, the integrity breach could undermine trust in data pipelines and analytics. Organizations in sectors like finance, telecommunications, and government, which rely heavily on real-time data processing, may face operational risks and reputational damage if exploited. The lack of authentication and user interaction requirements increases the attack surface, making remote exploitation feasible. However, the absence of known exploits in the wild suggests a window for mitigation before active attacks emerge.

European organizations should take immediate steps to mitigate CVE-2025-27522 by upgrading Apache InLong to version 2.2.0 or later, which contains the official fix. If upgrading is not immediately feasible, applying the patch from pull request #11732 is recommended to address the vulnerability. Additionally, organizations should audit their data ingestion and serialization workflows to ensure that untrusted data sources are validated and sanitized before processing. Implement network segmentation and strict access controls to limit exposure of Apache InLong services to untrusted networks. Employ runtime application self-protection (RASP) or intrusion detection systems (IDS) to monitor for anomalous deserialization activities. Regularly review and update security policies related to data pipeline components and conduct penetration testing focused on serialization and deserialization vectors. Finally, maintain up-to-date threat intelligence to detect any emerging exploit attempts targeting this vulnerability.