Tighten deserialization allowlist regex to require full-string match#66499
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potiuk wants to merge 2 commits intoapache:mainfrom
Open
Tighten deserialization allowlist regex to require full-string match#66499potiuk wants to merge 2 commits intoapache:mainfrom
potiuk wants to merge 2 commits intoapache:mainfrom
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The ``allowed_deserialization_classes_regexp`` allowlist used ``re.match()``, which only anchors at the start of the string. A pattern like ``airflow\.models\.Variable`` therefore also admitted classnames such as ``airflow.models.Variable_Malicious``. Switch to ``re.fullmatch()`` so the admin's pattern matches the entire classname; document the semantics in the config description so operators know to use ``.*`` for prefix-style allowances.
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Tighten the deserialization allowlist (
[core] allowed_deserialization_classes_regexp)to use
re.fullmatch()instead ofre.match(). Previously a pattern such asairflow\.models\.Variableadmitted not only the intended class but alsoairflow.models.Variable_Malicious—re.matchonly anchors at the startof the string. Using
fullmatchrequires the pattern to match the entireclassname, eliminating the prefix-bypass footgun.
Updated the config description so admins know patterns are full-match and
that
.*is needed for prefix-style allowances. Updated the existing testthat relied on prefix-match semantics, and added a dedicated test for the
bypass scenario.
Compatibility note for reviewers
This is a behaviour change for any deployment that configured
allowed_deserialization_classes_regexpwith patterns relying onprefix-match semantics (e.g.
airflow\.models\.to mean "any class underairflow.models"). Such deployments need to add.*to the pattern.The default value is empty, so out-of-the-box deployments are unaffected.
Default off, admin-only config — leaving the newsfragment decision to the
reviewer.
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Generated-by: Claude Opus 4.7 (1M context) following the guidelines