CVE-2026-1847
Published: 10 February 2026
Summary
CVE-2026-1847 is a medium-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Mongodb Mongodb. Its CVSS base score is 6.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 19.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
This control implements explicit throttling on session allocation, addressing the weakness of allocating resources without limits.
Plan testing exercises resource allocation limits and throttling during simulated failures, directly addressing weaknesses that allow unbounded resource use.
Contingency plan updates ensure recovery strategies address unbounded resource allocation, making it harder for attackers to exploit lack of throttling to cause prolonged outages.
Provides continuity when unbounded resource allocation at the primary site leads to exhaustion and downtime.
Alternate services allow operations to continue when primary allocation of resources lacks limits or throttling.
Explicit planning of security-related actions requires defining limits, windows, and resource allocations, making allocation without throttling far less likely.
Measures of performance include tracking allocation behavior and throttling effectiveness, reducing the window for resource exhaustion attacks.
Imposes an inactivity-based limit on network resource allocation, throttling the number of concurrently held connections.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
CVE directly enables application-level DoS via crafted document insertion exploiting unbounded resource allocation in MongoDB replication.
NVD Description
Inserting certain large documents into a replica set could lead to replica set secondaries not being able to fetch the oplog from the primary. This could stall replication inside the replica set leading to server crash.
Deeper analysisAI
CVE-2026-1847 is a denial-of-service vulnerability in MongoDB replica sets. Inserting certain large documents into a replica set can prevent secondaries from fetching the oplog from the primary, stalling replication and potentially causing server crashes. The issue is rated with a CVSS v3.1 base score of 6.5 (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) and is associated with CWE-770 (Allocation of Resources Without Limits or Throttling).
A low-privileged authenticated user with network access can exploit this vulnerability by inserting specially crafted large documents into the replica set. This triggers the replication failure on secondaries, leading to stalled operations and high-impact availability disruptions, including server crashes, without affecting confidentiality or integrity.
For mitigation details, refer to the MongoDB JIRA ticket at https://jira.mongodb.org/browse/SERVER-113532.
Details
- CWE(s)