PyMongo 4.12.1 Released

We are pleased to announce the 4.12.1 release of PyMongo - MongoDB’s Python Driver.

Changes in Version 4.12.1 (2025/04/29)

Version 4.12.1 is a bug fix release.

  • Fixed a bug that could raise UnboundLocalError when creating asynchronous connections over SSL.
  • Fixed a bug causing SRV hostname validation to fail when resolver and resolved hostnames are identical with three domain levels.
  • Fixed a bug that caused direct use of pymongo.uri_parser to raise an AttributeError.
  • Fixed a bug where clients created with connect=False and a “mongodb+srv://” connection string
    could cause public pymongo.MongoClient and pymongo.AsyncMongoClient attributes (topology_description,
    nodes, address, primary, secondaries, arbiters) to incorrectly return a Database, leading to type
    errors such as: “NotImplementedError: Database objects do not implement truth value testing or bool()”.
  • Fixed a bug where MongoDB cluster topology changes could cause asynchronous operations to take much longer to complete
    due to holding the Topology lock while closing stale connections.
  • Fixed a bug that would cause AsyncMongoClient to attempt to use PyOpenSSL when available, resulting in errors such as
    “pymongo.errors.ServerSelectionTimeoutError: ‘SSLContext’ object has no attribute ‘wrap_bio’”.

Issues Resolved

See the PyMongo 4.12.1 release notes in JIRA for the list of resolved issues in this release.

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