MongoDB Server Aggregation UAF in Batch Size 0
CVE-2026-96297 Published on October 13, 2026
MongoDB Server may disclose process memory via a crafted `$_internalApplyOplogUpdate` aggregation pipeline
Use of freed memory in the aggregation feature of MongoDB Server can cause the server to read data from a memory area after it has been released. When an internal aggregation stage is combined with a batch size of 0, the server may read from memory that is no longer in use. Because that memory can be reused for other data before it is read, query results returned to the client may contain unrelated data from the server process. Depending on the state of memory at the time, the server process may also terminate unexpectedly. The behavior can occur when an authenticated user with read privileges runs an aggregate command that combines these two settings.
Vulnerability Analysis
CVE-2026-96297 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Type
What is a Dangling pointer Vulnerability?
Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.
CVE-2026-96297 has been classified to as a Dangling pointer vulnerability or weakness.
Products Associated with CVE-2026-96297
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Affected Versions
MongoDB Server:- Version 8.3.0 and below 8.3.13 is affected.
- Version 8.0 and below 8.0.34 is affected.
- Version 7.0 and below 7.0.45 is affected.
- Version 9.0 and below 9.0.2 is affected.