CVE-2025-14847 is a vulnerability classified under CWE-130 (Improper Handling of Length Parameter Inconsistency) affecting MongoDB Server versions 3.6 through 8.2 prior to their respective patched releases. The issue arises from mismatched length fields in Zlib compressed protocol headers used by MongoDB's internal communication protocols. Specifically, the length parameters in the compressed data headers are not properly validated, allowing an unauthenticated remote attacker to trigger a read of uninitialized heap memory. This can lead to the disclosure of sensitive information residing in memory, potentially including database contents or internal server state. The vulnerability does not require any authentication or user interaction, making it remotely exploitable over the network with low complexity. The CVSS 4.0 base score is 8.7, indicating a high severity due to the combination of network attack vector, no required privileges or user interaction, and high confidentiality impact. The vulnerability affects all major supported MongoDB versions from 3.6 to 8.2, reflecting a long-standing issue in the protocol's handling of compressed data. No public exploits have been reported yet, but the broad impact and ease of exploitation make it a critical concern. MongoDB users are advised to upgrade to versions 7.0.28, 8.0.17, 8.2.3, 6.0.27, 5.0.32, 4.4.30, or later to remediate the issue. The vulnerability underscores the risks of improper input validation in compression protocols and the potential for memory disclosure attacks in database servers.

For European organizations, this vulnerability poses a significant risk of sensitive data exposure from MongoDB servers, which are widely used in enterprise applications, cloud services, and critical infrastructure. The ability for an unauthenticated attacker to remotely read uninitialized heap memory can lead to leakage of confidential information such as user data, credentials, or internal configuration details. This can undermine data privacy compliance obligations under GDPR and other regulations, potentially resulting in legal and financial penalties. Additionally, the exposure of internal memory contents could facilitate further attacks, including privilege escalation or lateral movement within networks. Organizations relying on MongoDB for critical business functions or storing sensitive personal or financial data are particularly vulnerable. The broad range of affected versions means many deployments may be at risk if not promptly updated. The lack of known exploits in the wild provides a window for proactive mitigation, but also means attackers may develop exploits targeting European entities given their extensive use of MongoDB. Overall, the impact includes confidentiality breaches, reputational damage, regulatory consequences, and increased risk of follow-on attacks.

European organizations should immediately inventory all MongoDB deployments to identify affected versions ranging from 3.6 to 8.2 prior to the patched releases. The primary mitigation is to upgrade MongoDB Server to the fixed versions: 7.0.28, 8.0.17, 8.2.3, 6.0.27, 5.0.32, 4.4.30, or later. Where immediate upgrades are not feasible, organizations should restrict network access to MongoDB instances by implementing strict firewall rules limiting connections to trusted hosts and internal networks only. Enabling network encryption (TLS) and authentication can reduce exposure, although this vulnerability does not require authentication to exploit. Monitoring network traffic for unusual patterns in compressed protocol headers may help detect exploitation attempts. Additionally, applying runtime memory protection mechanisms such as AddressSanitizer or enabling heap memory initialization options can mitigate the risk of memory disclosure. Organizations should also review and harden MongoDB configuration settings to minimize attack surface, including disabling unused features and enforcing least privilege access controls. Finally, maintaining an incident response plan for potential data breaches involving database memory disclosure is recommended.