What happened
A security vulnerability has been identified in MongoDB Server that allows an unauthenticated network user to cause a denial of service on specific types of replica set members. The issue involves an assertion in the server’s read concern processing logic that can be triggered without requiring user authentication. This assertion relies on certain assumptions about the internal state of the server, which are not valid for all configurations. As a result, when the assertion is reached under these conditions, the affected server process terminates unexpectedly, impacting data availability.
The vulnerability has been assigned the identifier CVE-2026-82064 and is characterised as high severity due to its potential to disable affected database services remotely. It does not enable access to or alteration of data directly nor does it permit remote code execution, but the denial of service could disrupt operations or availability of data stored within the impacted systems. The issue is primarily due to a flaw in the handling of read concern logic within the server’s processing mechanisms.
The report confirms that this flaw is reachable remotely over a network, with no prior access or user interaction required. Attackers can exploit the vulnerability simply by connecting to an exposed network service, making it critical to address exposure through network controls such as segmentation or access restrictions, alongside timely application of patches when available.
At the present time, no patch has been publicly released to remediate this vulnerability. The authoritative analysis indicates that this vulnerability results from a weakness classified as CWE-617, involving insecure temporary data handling in software.
Who is affected
Organisations running MongoDB Server with affected replica set configurations are potentially vulnerable to this issue. The impact is limited to certain configurations where the read concern processing logic may be reached without authentication, leading to the risk of server termination and resulting service disruption. All such deployments should be considered at risk until mitigations or patches are available.
Recommended actions
- Review network security measures to limit access to the MongoDB Server, including network segmentation and access control lists, to prevent unauthenticated connections from reaching the service.
- Monitor exposed services for unusual activity or indications of potential exploitation attempts.
- Prepare for applying patches or configuration changes once manufacturers release updates addressing this vulnerability.
Indicators of compromise
This section is not supplied; no indicators of compromise are currently available.
