CodeQL 2.27.3 introduces Python 3.15 language feature support and JSON data extensions. It also adds new built-ins and data-flow capabilities to improve analysis coverage across languages.
JSON DATA EXTENSIONS AND JSON SYNTAX
Data extension files now support JSON syntax, using the same structure as YAML data extensions. Java-style comments are supported. CodeQL parses files with the .json extension as JSON and continues to parse all other files as YAML.
PYTHON 3.15 FEATURES AND PYTHON EXTRACTOR
The Python extractor now supports Python 3.15 syntax, including unary plus in match literal patterns and Unicode 17 identifiers. The changelog also mentions new built-ins such as frozendict and sentinel, with data-flow modeling for frozendict construction.
QUALITY IMPROVEMENTS AND FALSE POSITIVES
The update includes targeted improvements that reduce false positives in several queries (e.g., cpp/resource-not-released-in-destructor, cs/simplifiable-boolean-expression, java/ssrf, java/unvalidated-url-redirection). These changes may improve accuracy, though the announcement does not provide empirical metrics.
OPERATIONAL NOTES AND GOVERNANCE
An opt-in AI threat model for LLM-generated data is introduced, and the changelog notes that users can define their own sources with data extensions. When configuring private registries, CodeQL now passes required proxy and certificate environment variables to the NuGet CLI.
BROADER IMPACT AND NEXT STEPS
The release includes broader language coverage updates, data extension capabilities, and workflow considerations for CodeQL users. The changelog points readers to a complete changelog for version 2.27.3 for a full list of changes and notes that this functionality will be included in GHES 3.24.
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SOURCES
- Archive: 2026 - GitHub Changelog: CodeQL 2.27.3 adds Python 3.15 features and JSON data extensions Published · Primary source





