cti-stix-validator v3.3.0 Release Notes

Release date: 2026-05-12

Overview

cti-stix-validator v3.3.0 updates the supported Python versions, refreshes schema support, improves validation behavior around timestamp comparisons, and includes several test and documentation improvements.

This release also includes performance improvements for schema lookup caching and additional fixes around STIX object reference validation.

Highlights

• Updated supported Python versions, including support for Python 3.14.
• Added the required minimum Python version metadata.
• Improved timestamp comparison handling to avoid validation errors when malformed timestamp values are encountered.
• Updated schema pinning to the latest STIX 2.1 schema commit.
• Improved schema lookup performance through caching.
• Fixed object reference validation to prevent invalid SDO usage in SCO object reference properties.
• Updated maintainers list and ReadTheDocs configuration.
• Added and improved tests for timestamp handling, campaign objects, STIX 2.0 Course of Action objects, and object reference validation.

Changes

Python Support

• Bumped the latest supported version.
• Added the required minimum Python version.
• Updated the list of supported Python versions.
• Added Python 3.14 support.

Validation Fixes

• Fixed timestamp field comparison to avoid exceptions when comparing invalid or improperly formatted timestamp values.
• Added checks to ensure both timestamp values are valid datetime objects before comparison.
• Improved handling of cases where one timestamp may still be a string due to invalid formatting.
• Fixed additional datetime comparison issues that could previously lead to incorrect negative validation results.

STIX Schema and Object Reference Validation

• Updated schema pinning to the latest STIX 2.1 schema commit.
• Improved validation for object_refs.
• Added schema allow/deny patterns to limit object_refs to SCO and SRO where appropriate.
• Fixed an issue where SDOs could be incorrectly allowed in SCO object reference properties.

Tests

• Removed redundant test coverage for start and end fields in network traffic objects.
  • The existing test for end and is_active is sufficient, since there is no validation check on start and end time ordering.
• Added missing test cases for campaign objects.
• Added missing test cases for STIX 2.0 Course of Action objects.
• Added tests for timestamp value formatting and comparison.
• Added and improved tests for invalid object_refs.

Performance

• Improved performance by caching schema lookup operations.
• Improved schema discovery across different directories.

Documentation and Project Maintenance

• Added pinning documentation.
• Added required ReadTheDocs configuration.
• Updated the maintainers list.
• Updated changelog entries for previous releases.
• Fixed formatting issues reported by flake8.
• Updated CI configuration.

Contributors

This release includes work from:

• Christian Studer
• Emily Ratliff
• Rich Piazza
• Dave Morse
• Jordan A. Voss
• Chris Lenk
• openmorse
• Alexandre Dulaunoy

Summary

cti-stix-validator v3.3.0 is primarily a maintenance and compatibility release. It improves Python version support, strengthens timestamp validation behavior, refreshes schema support, improves performance through caching, and fixes object reference validation edge cases.