CVE-2025-64683 is a vulnerability identified in JetBrains Hub, a platform widely used for user management and collaboration in software development environments. The issue is classified under CWE-362, indicating a race condition that leads to a time-of-check to time-of-use (TOCTOU) flaw in the Users API. This race condition allows an attacker to perform unauthorized information disclosure by exploiting the timing gap in the API's handling of user data requests. The vulnerability affects all versions of JetBrains Hub prior to 2025.3.104432. The CVSS 3.1 base score of 5.3 reflects that the attack vector is network-based (AV:N), requires no privileges (PR:N), and no user interaction (UI:N), but only impacts confidentiality (C:L) without affecting integrity or availability. The flaw enables attackers to retrieve sensitive user information, potentially including usernames, email addresses, or other personal data managed by the Hub. Although no public exploits are reported yet, the vulnerability's presence in a critical user management component poses a risk for organizations relying on JetBrains Hub for identity and access control. The absence of a patch link suggests that the fix is either forthcoming or integrated into a future release version 2025.3.104432. Organizations must be aware of this vulnerability to prevent unauthorized data exposure and potential downstream attacks leveraging leaked user information.

For European organizations, the primary impact of CVE-2025-64683 is unauthorized disclosure of sensitive user information managed within JetBrains Hub. This can lead to privacy violations, regulatory non-compliance (e.g., GDPR), and increased risk of targeted phishing or social engineering attacks using exposed user data. Since JetBrains Hub is often integrated into development pipelines and identity management systems, leaked information could facilitate lateral movement or credential stuffing attacks. The vulnerability does not directly affect system integrity or availability, but the confidentiality breach alone can have significant reputational and legal consequences. Organizations in sectors with strict data protection requirements, such as finance, healthcare, and government, are particularly vulnerable. The ease of exploitation (no authentication or user interaction required) increases the likelihood of opportunistic attacks, especially in environments with internet-facing JetBrains Hub instances.

1. Upgrade JetBrains Hub to version 2025.3.104432 or later as soon as the patch is officially released to address the race condition in the Users API. 2. Until patching is possible, restrict network access to the JetBrains Hub Users API by implementing IP whitelisting or VPN-only access to limit exposure. 3. Enforce strict API authentication and authorization policies to ensure only legitimate users and services can query user information. 4. Monitor API access logs for unusual or repeated requests to the Users API that could indicate exploitation attempts. 5. Conduct regular audits of user data exposure and review integration points with other systems to minimize sensitive data leakage. 6. Educate development and security teams about the vulnerability and encourage prompt application of security updates. 7. Consider implementing Web Application Firewalls (WAF) with custom rules to detect and block suspicious API calls targeting the Users API endpoints.