[3.12] gh-149079: Fix O(n^2) canonical ordering in unicodedata.normalize() (GH-149080) - #150843
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…normalize() (pythonGH-149080) Replace the insertion sort used for canonical ordering of combining characters with a hybrid approach: insertion sort for short runs (< 20) and counting sort for longer runs, reducing worst-case complexity from O(n^2) to O(n). This prevents denial of service via crafted Unicode strings with many combining characters in alternating CCC order. (cherry picked from commit 991224b) Co-authored-by: Seth Larson <[email protected]> Co-authored-by: ch4n3-yoon <[email protected]> Co-authored-by: Seokchan Yoon <[email protected]> Co-authored-by: Stan Ulbrych <[email protected]> Co-authored-by: Bénédikt Tran <[email protected]> Co-authored-by: Serhiy Storchaka <[email protected]> Co-authored-by: Maurycy Pawłowski-Wieroński <[email protected]>
This was referenced Jun 3, 2026
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needs backport to 3.10
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GH-155158 is a backport of this pull request to the 3.11 branch. |
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GH-155159 is a backport of this pull request to the 3.10 branch. |
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…ize() (GH-149080) (GH-150843) (#155158) [3.12] gh-149079: Fix O(n^2) canonical ordering in unicodedata.normalize() (GH-149080) (GH-150843) Replace the insertion sort used for canonical ordering of combining characters with a hybrid approach: insertion sort for short runs (< 20) and counting sort for longer runs, reducing worst-case complexity from O(n^2) to O(n). This prevents denial of service via crafted Unicode strings with many combining characters in alternating CCC order. (cherry picked from commit 991224b) (cherry picked from commit d3ab945) Co-authored-by: Petr Viktorin <[email protected]> Co-authored-by: Seth Larson <[email protected]> Co-authored-by: ch4n3-yoon <[email protected]> Co-authored-by: Seokchan Yoon <[email protected]> Co-authored-by: Stan Ulbrych <[email protected]> Co-authored-by: Bénédikt Tran <[email protected]> Co-authored-by: Serhiy Storchaka <[email protected]> Co-authored-by: Maurycy Pawłowski-Wieroński <[email protected]>
pablogsal
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…ize() (GH-149080) (GH-150843) (#155159) [3.12] gh-149079: Fix O(n^2) canonical ordering in unicodedata.normalize() (GH-149080) (GH-150843) Replace the insertion sort used for canonical ordering of combining characters with a hybrid approach: insertion sort for short runs (< 20) and counting sort for longer runs, reducing worst-case complexity from O(n^2) to O(n). This prevents denial of service via crafted Unicode strings with many combining characters in alternating CCC order. (cherry picked from commit 991224b) (cherry picked from commit d3ab945) Co-authored-by: Petr Viktorin <[email protected]> Co-authored-by: Seth Larson <[email protected]> Co-authored-by: ch4n3-yoon <[email protected]> Co-authored-by: Seokchan Yoon <[email protected]> Co-authored-by: Stan Ulbrych <[email protected]> Co-authored-by: Bénédikt Tran <[email protected]> Co-authored-by: Serhiy Storchaka <[email protected]> Co-authored-by: Maurycy Pawłowski-Wieroński <[email protected]> Co-authored-by: Hugo van Kemenade <[email protected]>
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Replace the insertion sort used for canonical ordering of combining characters with a hybrid approach: insertion sort for short runs (< 20) and counting sort for longer runs, reducing worst-case complexity from O(n^2) to O(n). This prevents denial of service via crafted Unicode strings with many combining characters in alternating CCC order.
(cherry picked from commit 991224b)
Co-authored-by: Seth Larson [email protected]
Co-authored-by: ch4n3-yoon [email protected]
Co-authored-by: Seokchan Yoon [email protected]
Co-authored-by: Stan Ulbrych [email protected]
Co-authored-by: Bénédikt Tran [email protected]
Co-authored-by: Serhiy Storchaka [email protected]
Co-authored-by: Maurycy Pawłowski-Wieroński [email protected]
unicodedata.normalize("NFC")canonical ordering #149079