The $_internalConvertBucketIndexStats stage used PauseExecution as a way to signal "skip this document" when an index stats conversion failed. But PauseExecution is not a general purpose skip mechanism, but rather a TeeBuffer-internal signal used solely by $facet to coordinate its sub-pipelines. When this stage is placed before $facet in a pipeline, TeeBuffer receives the unexpected PauseExecution from upstream and hits a hard invariant assertion, crashing mongod.
This issue can occur when running an aggregation pipeline that uses the internal $exchange stage configured with key-range partitioning and order-preserving delivery. If a single key range produces enough documents to fill its exchange buffer (that is, many results are routed to the same consumer), the server reaches the code path where a full per-consumer buffer is detected but the internal "high watermark" for that key range is not updated as intended.
An authenticated user can cause a MongoDB server to crash or return incorrect results by creating documents that interfere with internal metadata processing during query execution. This stems from insufficient separation between user-controlled document fields and internal metadata in certain execution paths.
An authorized user could trigger a server crash by running a query with a 2dsphere index on a field that stores a GeoJSON GeometryCollection containing a Polygon with a strict-winding CRS.
Strict-winding polygons are intentionally unsupported for indexing, but the guard that rejects them does not inspect members of a GeometryCollection, allowing the unsafe path to be reached which ends with an ensuing null-pointer dereference.
The $_internalApplyOplogUpdate aggregation pipeline stage can be used to execute a document diff containing a malformed binary diff to return memory out-of-bounds or crash the server. $_internalApplyOplogUpdate can be executed by any authenticated user with access to the aggregate command.
MongoDB server may log authentication parameters, including credentials, to the server log during SASL authentication. When connection health metric logging is enabled, the full authentication parameters are written to the log without redaction.
A vulnerability in MongoDB Server's BSON validation logic allows an unauthenticated user to crash the mongod process by sending a specially crafted message. The BSON validator's handling of certain nested binary data structures permits uncontrolled mutual recursion between validation functions, where each re-entry resets internal depth tracking.