Key takeaways
- Aikido Security tracked this MongoDB vulnerability before it was indexed in the NVD, based on upstream vendor fixes and internal threat intelligence ingestion.
- The issue (CVE-2025-14847), known as MongoBleed, allows unauthenticated, network-level attackers to extract fragments of uninitialized server memory.
- No credentials are required if the MongoDB server is reachable over the network and zlib compression is enabled.
- Aikido customers were already able to detect the vulnerability via container scanning, VM scanning, Kubernetes scanning, while new CSPM rules have been added to reinforce prevention to exposed MongoDB services.
How to see if you are affected
Option 1: Use Aikido Security
You are affected if Aikido reports:
- A vulnerable MongoDB version running in containers, virtual machines, or Kubernetes
- Network-exposed MongoDB services
- Misconfigured cloud or cluster-level access controls
These checks are available in the free version of Aikido Security.
Option 2: Manual validation
You are likely affected if:
- Your MongoDB version is listed in the affected versions table below
- Your MongoDB port is reachable over the network
- zlib compression is enabled (default in many deployments)
Remediation steps
Immediate remediation (recommended)
Upgrade MongoDB to a patched version:
- 8.2.3
- 8.0.17
- 7.0.28
- 6.0.27
- 5.0.32
- 4.4.30
Temporary mitigation (if upgrade is not immediately possible)
- Disable zlib compression and switch to snappy, zstd, or no compression
- Restrict network access to MongoDB using firewalls, security groups, or Kubernetes NetworkPolicies
- Remove any unnecessary public exposure
Who is impacted
This vulnerability impacts organizations running self-managed MongoDB servers on affected versions where:
- The MongoDB service is reachable over the network
- zlib compression is enabled
This includes MongoDB deployed on:
- Virtual machines
- Containers
- Kubernetes clusters
- Cloud environments with misconfigured networking
What is Mongobleed?
MongoDB disclosed a vulnerability in its network transport layer that can result in uninitialized server memory being sent to clients. Because the issue occurs during message decompression, it is triggered before authentication, allowing unauthenticated attackers to exploit it remotely.
The vulnerability is tracked as CVE-2025-14847.
What is the attack about?
The attack targets MongoDB’s handling of compressed network messages. By sending specially crafted compressed payloads, an attacker can cause MongoDB to miscalculate the length of decompressed data and include unintended memory contents in its response.
Attacker intent
The vulnerability enables information disclosure, which may be used for reconnaissance, data harvesting, or chaining with other attacks.
Initial impact
- Authentication required: No
- User interaction required: None
- Attack surface: Network-exposed MongoDB instances
- Exploit complexity: Low
Broader impact
Even partial memory disclosure can reveal sensitive application data, expose internal server state, and assist attackers in lateral movement.
Technical deep dive
Where the vulnerability lived
The issue resides in MongoDB’s network transport compression layer, specifically in the zlib decompression logic.
What it could do
Incorrect handling of decompressed message lengths caused MongoDB to return uninitialized heap memory beyond the intended payload, resulting in memory disclosure.
Proof of concept (high level)
MongoDB’s own regression tests and patches demonstrate that malformed compressed frames could reliably trigger the issue, confirming exploitability under attacker-controlled input.
Why these vulnerabilities occur
This class of vulnerability typically arises from complex memory management in high-performance network code, insufficient validation of attacker-controlled input, and mismatches between allocated buffer sizes and actual data length.
Scope of attack
Workloads are at risk if they:
- Run vulnerable MongoDB versions
- Allow inbound network access to MongoDB
- Use default compression settings
- Lack network segmentation or runtime visibility
How Aikido Security helps
Aikido helps teams reduce exposure to vulnerabilities like CVE-2025-14847 by focusing on early signals and real runtime risk, not just CVE listings.
- Early awareness
Aikido tracks upstream vendor fixes and advisories in Aikido Intel, so teams can see critical issues before they appear in the NVD or most scanners. - Where it’s actually running
Aikido shows whether vulnerable MongoDB versions are present in containers, VMs, or Kubernetes, and whether they are network exposed. - Fewer risky defaults
Built-in posture checks help catch unsafe configurations like exposed databases that turn bugs into incidents.
This lets developers identify and fix real exposure quickly without waiting on delayed CVE feeds. Learn more about Aikido Security here.
Conclusion
CVE-2025-14847 is a critical MongoDB vulnerability that allows unauthenticated attackers to leak server memory via zlib compression.
Appendix: Affected MongoDB Versions
MongoDB 8.2
- Vulnerable: 8.2.0 – 8.2.2
- Fixed: 8.2.3
MongoDB 8.0
- Vulnerable: 8.0.0 – 8.0.16
- Fixed: 8.0.17
MongoDB 7.0
- Vulnerable: 7.0.0 – 7.0.27
- Fixed: 7.0.28
MongoDB 6.0
- Vulnerable: 6.0.0 – 6.0.26
- Fixed: 6.0.27
MongoDB 5.0
- Vulnerable: 5.0.0 – 5.0.31
- Fixed: 5.0.32
MongoDB 4.4
- Vulnerable: 4.4.0 – 4.4.29
- Fixed: 4.4.30
MongoDB 4.2
- Vulnerable: All versions
- Fixed: No fix available
MongoDB 4.0
- Vulnerable: All versions
- Fixed: No fix available
MongoDB 3.6
- Vulnerable: All versions
- Fixed: No fix available
References
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