MongoDB MongoBleed Exploitation CVE-2025-14847

Dec 29

BLUF

Unauthenticated remote attackers are actively exploiting a high-severity information leakage vulnerability in MongoDB's Zlib compression protocol. The exploit, dubbed "MongoBleed," allows for the potential extraction of sensitive data such as session tokens, passwords, and API keys from exposed servers.

Executive Cost Summary

This cost analysis was developed by the CyberDax team using expert judgment and assisted analytical tools to support clarity and consistency.

For organizations operating vulnerable MongoDB instances with network compression enabled and confirmed or suspected MongoBleed exploitation:

Low-end total cost: $600,000 – $900,000
(Rapid detection, limited exposure, no regulated data confirmed)
Typical expected range: $1.1M – $2M
(Credential rotation, external IR support, compliance review)
Upper-bound realistic scenarios: $2.5M – $4M
(Sensitive data exposure, regulatory involvement, prolonged assurance efforts)

Key cost driver:

Costs are driven less by system outages and more by uncertainty. The MongoBleed vulnerability undermines confidence in data confidentiality by leaking uninitialized memory, forcing organizations to assume potential exposure of credentials, tokens, and sensitive data fragments. As a result, the dominant expenses stem from forensic validation, credential replacement, legal review, and governance assurance rather than traditional breach containment or rebuild activities.

Targeted Sectors

Any organization using vulnerable versions of MongoDB servers with network compression enabled, specifically databases and potentially financial services/healthcare given the data types targeted.

Countries

· Global

Date of First Reported Activity

· December 26, 2025

Date of Last Reported Activity Update

· December 29, 2025

CVE-2025-14847

CVSS v3.1

(8.7) AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Nessus ID

· 279586

· 279580

Is CVE-2025-14847 on the KEV List?

· Yes

CISA patch by date

· January 19, 2026

URL link to patch information

· hxxps://jira.mongodb.org/browse/SERVER-115508

APT Names

· This has not been associated with any APT groups at this time

Associated Criminal Organization Names

· This has not been associated with any criminal organizations at this time

IOCs

Anomalous Network Traffic

· The core of the exploit involves an attacker sending specially crafted requests over the network to a reachable MongoDB instance. Monitoring for unusual spikes in traffic to MongoDB ports (default is 27017), particularly with mismatched length fields in zlib-compressed protocol headers, could serve as an indicator.

Unusual Server Responses

· The vulnerability causes the server to return uninitialized heap memory contents in its responses. Detection would require deep packet inspection of the MongoDB traffic to identify responses containing data fragments that do not match expected query results (e.g., sensitive data, credentials, or other cached information).

Unusual memory usage patterns on MongoDB server processes.

Tools Used in Campaign

· Custom scripts/tools leveraging public PoC exploit code.

TTPs (Tactics, Techniques, and Procedures):

· T1046 Network Service Scanning

o Used to discover vulnerable, internet-facing MongoDB instances.

· T1190 Exploitation of Public-Facing Application

o The primary method of initial access by exploiting the unauthenticated zlib flaw.

· T1210 Exploitation of Remote Services

o Leveraging the vulnerability to read sensitive server memory without valid credentials.

· T1005 Data from Local System

o Extracting fragments of sensitive information, such as credentials and API keys, directly from the host's memory.

· T1213 Data from Information Repositories

o Using the vulnerability to leak data stored within the database application environment.

· T1078 Valid Accounts: Utilizing leaked credentials from the memory disclosure for persistence or lateral movement.

Malware Names

· No specific malware associated with this exploit; attackers are using the vulnerability directly to leak memory.

Suggested rules / potential hunts

Suricata Rules

Specific rules would involve detecting anomalous Zlib compression headers or unusual response sizes from MongoDB services. (Generic example: alert tcp any any -> any <MONGODB_PORT> (msg:"Potential MongoBleed CVE-2025-14847 exploitation attempt"; ...) - specific payload patterns are needed for effective detection).

SentinelOne Rules

High-Velocity Connection Monitoring

Search for endpoints with a high rate of inbound connections on the default MongoDB port (27017) from external or unexpected internal IPs.

EventType = "IP Connect" AND NetPort = 27017 grouped by SrcIP to find outliers with ≥500 connections/min.

Monitor for unexpected behavior from the mongod process following a surge in connections, such as memory spikes or crashes.

ProcessName = "mongod.exe" (or mongod on Linux) followed by Process Rollback or Unexpected Termination events.

Splunk Hunts

index=* sourcetype=mongodb (CVE-2025-14847 OR "MongoBleed")

index=* sourcetype=network_traffic dest_port=<MONGODB_PORT> (bytes_out>bytes_in*X OR "zlib compression header anomaly") (requires traffic inspection and normal baseline).

Delivery Method

· Unauthenticated network-based attack by sending crafted compressed messages to exposed MongoDB ports.

Email Samples

· Not applicable

References

NVD

· hxxps://nvd.nist.gov/vuln/detail/CVE-2025-14847

Security Week

· hxxps://www.securityweek.com/fresh-mongodb-vulnerability-exploited-in-attacks/

The Hacker News

· hxxps://thehackernews.com/2025/12/mongodb-vulnerability-cve-2025-14847.html

Tenable

· hxxps://www.tenable.com/cve/CVE-2025-14847/plugins

WIZ IO

· hxxps://www.wiz.io/blog/mongobleed-cve-2025-14847-exploited-in-the-wild-mongodb

JIRA Mongodb Org