CVE-2026-82076: 
MongoDB Analisi e mitigazione delle vulnerabilità

CVE-2026-82076 is an integer overflow vulnerability in the query planning component of MongoDB Server that allows an authenticated user with ordinary database-level read/write privileges to cause unbounded memory consumption, resulting in a denial of service. The vulnerability was published on September 8, 2026, and is currently awaiting full NVD analysis. Affected versions include MongoDB Server 7.0.0–7.0.40, 8.0.0–8.0.29, and 8.3.0–8.3.8. It carries a CVSS v3.1 base score of 6.5 (Medium) and a CVSS v4.0 base score of 7.1 (High) (Feedly, EUVD).

The root cause is an integer overflow or wraparound (CWE-190) in MongoDB Server's query planning component, mapped to CAPEC-92 (Forced Integer Overflow). When a specially crafted query is submitted, the overflow bypasses an internal resource limit designed to cap memory usage during query planning, causing the server to allocate memory without bound until the process is terminated by the operating system. Exploitation requires only low-privilege, authenticated network access with no user interaction and low attack complexity. The upstream issue is tracked as SERVER-128253 in MongoDB's Jira (Feedly, MongoDB Jira).

Successful exploitation results in complete availability loss for the affected MongoDB node — the server process terminates due to memory exhaustion, causing a denial of service for all databases hosted on that node. There is no confidentiality or integrity impact; the vulnerability is purely an availability concern. Because a single node failure can affect all databases it serves, multi-tenant or shared MongoDB deployments face broader service disruption (Feedly).

As of the publication date, there are no known public proof-of-concept exploits, no reported in-the-wild exploitation, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. The NVD SSVC assessment classifies exploitation as "none" and the attack as not automatable, reflecting the requirement for authenticated access. The EPSS score is 0.0, indicating a very low probability of exploitation in the near term (Feedly, EUVD).

1. Obtain credentials: Acquire valid MongoDB credentials with at least read/write privileges on any database — this could be through credential theft, phishing, or use of a low-privilege account already provisioned on the target.
2. Connect to the target: Establish a network connection to the MongoDB Server instance (default port 27017) using a MongoDB client or driver.
3. Craft a malicious query: Construct a specially crafted query designed to trigger the integer overflow in the query planning component, causing the planner to bypass its internal memory resource limit.
4. Submit the query: Execute the crafted query against the target database. The server's query planner begins consuming memory without bound.
5. Denial of service achieved: The MongoDB server process is terminated by the OS due to memory exhaustion, taking all hosted databases offline (Feedly, MongoDB Jira).

• Logs: MongoDB server logs showing sudden process termination or out-of-memory (OOM) kill events; log entries referencing query planning operations immediately before crash.
• System: Operating system OOM killer logs (e.g., /var/log/syslog or dmesg) showing the mongod process killed due to memory exhaustion.
• Network: Repeated authenticated connections from an unexpected or low-privilege account submitting complex or unusual queries to the MongoDB port (default 27017) shortly before service outage.
• Process: Abnormal spike in mongod process memory consumption visible via system monitoring tools (e.g., top, htop, Prometheus metrics) preceding a crash.

MongoDB has released fixed versions addressing this vulnerability: upgrade to MongoDB Server 7.0.41, 8.0.30, or 8.3.9 or later, depending on the release branch in use. Organizations unable to upgrade immediately should restrict database access to only trusted, necessary users and monitor for anomalous query patterns or memory spikes. Limiting network exposure of MongoDB instances (e.g., firewall rules, VPN-only access) reduces the attack surface by requiring an attacker to first obtain authenticated access (Feedly, EUVD).