CVE-2025-12383 is a race condition vulnerability classified under CWE-362 affecting Eclipse Jersey versions 2.45, 3.0.16, and 3.1.9. Jersey is a widely used open-source framework for developing RESTful web services in Java. The vulnerability arises from improper synchronization when concurrently executing code that manages SSL configurations. This flaw can cause the application to ignore critical SSL settings, including mutual TLS authentication, custom key stores, and trust stores. Under normal conditions, this may manifest as SSLHandshakeExceptions, but under specific race conditions, the application may erroneously trust insecure or malicious servers. This undermines the confidentiality and integrity guarantees of SSL/TLS, potentially allowing man-in-the-middle attacks or unauthorized data interception. The vulnerability has a CVSS 4.0 base score of 9.4, indicating critical severity with network attack vector, high attack complexity, no privileges required, no user interaction, and high impact on confidentiality and integrity. No public exploits are known yet, but the presence of a proof-of-concept demonstrates feasibility. The issue affects any Java application using the vulnerable Jersey versions for secure communications, especially those relying on SSL/TLS for authentication and encryption. The root cause is a concurrency bug where shared resources managing SSL parameters are accessed without proper synchronization, leading to inconsistent or skipped security checks during SSL handshake initialization. This can be exploited remotely by an attacker capable of intercepting or influencing network traffic to downgrade or bypass SSL protections. The vulnerability was reserved on 2025-10-28 and published on 2025-11-18, with no patches currently available, necessitating urgent mitigation strategies.

For European organizations, this vulnerability poses a significant risk to the security of web services that rely on Jersey for RESTful APIs, particularly those handling sensitive or regulated data such as financial transactions, personal health information, or government communications. The improper SSL configuration handling can lead to unauthorized trust in malicious servers, enabling man-in-the-middle attacks, data interception, and potential data breaches. This compromises confidentiality and integrity of communications, potentially violating GDPR and other data protection regulations. The high severity and network exploitability mean attackers can remotely target vulnerable services without authentication or user interaction. Critical sectors such as banking, healthcare, telecommunications, and public administration are especially vulnerable due to their reliance on secure web services. The disruption or compromise of these services could lead to financial loss, reputational damage, regulatory penalties, and erosion of public trust. Additionally, the lack of available patches increases exposure time, making proactive mitigation essential.

1. Monitor Eclipse Foundation announcements closely for official patches addressing CVE-2025-12383 and apply updates immediately upon release. 2. Until patches are available, implement application-level SSL/TLS validation to enforce strict certificate verification and reject connections that do not meet security policies. 3. Employ network-level protections such as TLS interception detection, anomaly-based intrusion detection systems, and strict firewall rules to limit exposure of vulnerable services. 4. Conduct thorough code reviews and testing to identify and mitigate concurrency issues in SSL configuration handling within custom Jersey integrations. 5. Consider temporary architectural changes to isolate or limit the use of vulnerable Jersey versions in critical systems. 6. Increase logging and monitoring of SSL handshake failures and unusual network traffic patterns to detect exploitation attempts early. 7. Educate development and security teams about the risks of race conditions in security-critical code and promote secure coding practices emphasizing thread safety. 8. If feasible, use alternative frameworks or versions not affected by this vulnerability until a secure Jersey release is available.