MongoBleed Vulnerability: Critical Threat to MongoDB Instances
A critical security vulnerability, CVE-2025-14847, has been identified in MongoDB, affecting over 87,000 instances globally. This vulnerability, dubbed "MongoBleed," has a CVSS score of 8.7 and allows unauthenticated attackers to remotely extract sensitive data from MongoDB server memory. The flaw is rooted in the zlib compression implementation used by MongoDB, which is enabled by default. Attackers can exploit this vulnerability by sending malformed network packets, potentially leaking user information, passwords, and API keys.
The vulnerability is particularly concerning for internet-exposed MongoDB servers, as it can be exploited without valid credentials or user interaction. Data shows that a significant number of vulnerable instances are located in the U.S., China, Germany, India, and France. Cloud environments are also at risk, with 42% having at least one vulnerable MongoDB instance. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added this vulnerability to its catalog of exploited vulnerabilities, emphasizing the need for immediate action.
To mitigate the risk, users are advised to update to the latest MongoDB versions: 8.2.3, 8.0.17, 7.0.28, 6.0.27, 5.0.32, and 4.4.30. Patches have been applied for MongoDB Atlas users. As a temporary workaround, disabling zlib compression and restricting network exposure of MongoDB servers are recommended. Monitoring logs for anomalous pre-authentication connections can also help detect potential exploitation attempts.
Threats and Vulnerabilities
CVE-2025-14847, known as MongoBleed, is a severe vulnerability in MongoDB's zlib compression implementation that allows unauthenticated attackers to leak sensitive data from server memory. The flaw arises from improper handling of length parameter inconsistencies in zlib compressed protocol headers, enabling attackers to access uninitialized heap memory.
The vulnerability affects MongoDB instances with zlib compression enabled by default, making them susceptible to data leakage through malformed network packets. This can result in unauthorized access to user information, passwords, and API keys. The vulnerability is particularly dangerous for internet-exposed servers due to its pre-authentication exploitability.
Industries relying on cloud environments are at significant risk, as 42% have at least one vulnerable MongoDB instance. The vulnerability also impacts the Ubuntu rsync package due to its use of zlib. While the exact nature of attacks exploiting this flaw remains unclear, the potential for widespread data breaches is high.
Client Impact
Clients using MongoDB are at risk of operational disruptions and data breaches due to the MongoBleed vulnerability. Unauthorized access to sensitive information such as user credentials and API keys could lead to financial losses and reputational damage. Organizations may face regulatory compliance challenges if data protection laws are violated due to a breach.
The vulnerability's pre-authentication nature makes it particularly concerning for internet-exposed servers, increasing the likelihood of exploitation without user interaction. Clients should be aware of the potential for audits or penalties if regulatory requirements are not met following a breach.
Mitigations
To mitigate the risks associated with the MongoBleed vulnerability, clients should consider the following actions:
- Update MongoDB instances to versions 8.2.3, 8.0.17, 7.0.28, 6.0.27, 5.0.32, and 4.4.30 to address the vulnerability.
- Disable zlib compression by configuring mongod or mongos with a networkMessageCompressors or net.compression.compressors option that omits zlib.
- Restrict network exposure of MongoDB servers by implementing firewall rules and access controls.
- Monitor MongoDB logs for anomalous pre-authentication connections that may indicate exploitation attempts.
- Apply patches for MongoDB Atlas if applicable and ensure all cloud environments are updated.
Implementing these measures will help reduce the risk of exploitation and protect sensitive data from unauthorized access. Clients should remain vigilant and continue monitoring for any updates or additional guidance from security authorities.
1898 & Co. Response
1898 & Co. is actively addressing the MongoBleed vulnerability by offering tailored security solutions to help clients mitigate this threat. Our team is focused on providing updates to existing security protocols and practices to ensure clients are protected against emerging threats like CVE-2025-14847.
We are collaborating with industry allies and government agencies to gather threat intelligence and provide clients with the most up-to-date information on potential risks and mitigations. Our ongoing research efforts aim to identify new vulnerabilities and develop effective strategies to counteract them.
Clients can benefit from our expertise in securing cloud environments and implementing robust access controls to minimize exposure to vulnerabilities like MongoBleed. We strive to deliver high-quality services that align with industry standards and support clients in maintaining a secure operational environment.