[3.12] gh-90949: expose Expat API to tune exponential expansion protections (GH-139368)#151401
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… protections (pythonGH-139368) Expose the XML Expat 2.7.2 APIs to tune protections against "billion laughs" [1] attacks. The exposed APIs are available on Expat parsers, that is, parsers created by `xml.parsers.expat.ParserCreate()`, as: - `parser.SetBillionLaughsAttackProtectionActivationThreshold(threshold)`, and - `parser.SetBillionLaughsAttackProtectionMaximumAmplification(max_factor)`. This completes the work in f04bea4, and improves the existing related documentation. [1]: https://en.wikipedia.org/wiki/Billion_laughs_attack (cherry picked from commit 6661123) (cherry picked from commit 19bc391) Co-authored-by: Stan Ulbrych <stan@python.org> Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
This was referenced Jun 12, 2026
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Expose the XML Expat 2.7.2 APIs to tune protections against "billion laughs" [1] attacks.
The exposed APIs are available on Expat parsers, that is, parsers created by
xml.parsers.expat.ParserCreate(), as:parser.SetBillionLaughsAttackProtectionActivationThreshold(threshold), andparser.SetBillionLaughsAttackProtectionMaximumAmplification(max_factor).This completes the work in f04bea4, and improves the existing related documentation.
[1]: https://en.wikipedia.org/wiki/Billion_laughs_attack (cherry picked from commit 6661123) (cherry picked from commit 19bc391)