CVE-2026-120678
Description
A flaw was found in the MongoDB C Driver. An unauthenticated attacker who controls a database server can cause a Denial of Service (DoS) against connecting client applications. Due to improper memory management when handling compressed server responses, the client library fails to release allocated memory, leading to unbounded memory consumption and application failure.
Statement
Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.
Mitigation
--- CME Mitigation Guidance (2026-11-04) ---
Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.
The highest-value action is to restrict mongo-c-driver client applications to trusted database endpoints to prevent ingestion of malformed OP_COMPRESSED responses: upgrade to mongo-c-driver 1.30.15, 2.5.8 (or the fixed Mongo C Driver builds), which free allocated decompressed reply buffers when parsing an OP_COMPRESSED response fails, closing malformed OP_COMPRESSED server replies. Until patched, this is a concern on Client applications connecting to database endpoints using mongo-c-driver, so Restrict client connections strictly to authenticated, trusted database server endpoints and protect the network path against traffic interception. As a compensating measure, Monitor cgroup memory pressure events and PSI to detect rapid memory consumption before system exhaustion occurs, Enforce RLIMIT_AS or memory limits on the client process using ulimit or prlimit to bound memory growth, Configure systemd WatchdogSec and automatic service restart to recover client services upon memory exhaustion or OOM termination, Constrain client process memory consumption via cgroups v2 to prevent unbounded growth from affecting host processes, and Periodically terminate and recycle client worker processes after handling requests to reclaim leaked memory. These controls limit blast radius and contain exploitation, but they do not fix the underlying memory leak defect — apply the upstream patch to fully remediate.
Highest-impact CME: CME-1010 cgroup Memory Pressure Monitoring (memory.events / PSI) (medium)
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (Other); DoS: Resource Consumption (Memory); DoS: Resource Consumption (CPU)
An attacker that can influence the allocation of resources that are not properly released could deplete the available resource pool and prevent all other processes from accessing the same type of resource. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.
Frequently Asked Questions
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