CVE-2026-120820MongoDB Server allocation without limits
CVE-2026-120820 is a allocation without limits in MongoDB Server, rated medium (5.3 on CVSS 4.0).
Why this priority: Medium severity, with no exploitation signal.
Published · Updated · NVD status: Awaiting Analysis
What it is
Resources are allocated without a cap, so a caller can exhaust them.
How it is reached
An attacker can exploit it over the network, with an ordinary user account, and nobody has to click anything.
What an attacker gains
The direct impact is limited: partial access to data or a partial outage. In practice, this kind of flaw lets an attacker exhaust CPU, memory or connections until the service stops answering.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- Upgrade MongoDB Server to a fixed version for your release line (9.0.7, 8.3.16, 8.0.37).
- Until it is patched, review who holds accounts that can reach it.
Description from NVD
MongoDB Server maintains an in-memory table of per-namespace statistics for operations that carry encrypted-field information. Entries are created for any namespace supplied in a request, with no limit on the number of entries and no way to remove entries that never corresponded to a real collection. A user with basic read privileges who repeatedly issues ordinary read commands referencing arbitrary namespace names may cause the server process to retain steadily increasing amounts of memory and to slow down on the affected code path; the memory is reclaimed only by restarting the process.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Public entry points and shared services that must stay up. The flaw sits between untrusted traffic and shared capacity.
Trust boundaries in play
- Authenticated network access. An account is needed, so exposure follows who can sign in: customers, partners or staff.
- Between untrusted traffic and shared capacity. An attacker who crosses it can exhaust CPU, memory or connections until the service stops answering.
Questions to answer about your own systems
- Where does MongoDB Server run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.