Description
The "stringprep" module didn't process characters from RFC 3454 tables B.2 or B.3 correctly: the latest Unicode codepoint attributes were used instead of the specified Unicode 3.2.0. This behavior would cause mismatches when processing domain names using IDNA 2003 (the "idna" codec) and the in_table_b2() function of the "stringprep" module. This only affects domain names containing characters that were not previously registered or had their Unicode attributes such as case-folding behavior updated since Unicode 3.2.0.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Python Software Foundation CPython
Default version status: unaffected
0 to < 3.10.22affected3.11.0 to < 3.11.17affected3.12.0 to < 3.12.15affected3.13.0 to < 3.13.16affected3.14.0 to < 3.14.8affected3.15.0a1 to < 3.15.0rc2affected
References
- https://github.com/python/cpython/pull/155293 ↗
- https://github.com/python/cpython/issues/155292 ↗
- https://mail.python.org/archives/list/security-announce@python.org/thread/EUHHTC6EV7HCLSUHP25C5VHSV4V2MUZN/ ↗
- https://github.com/python/cpython/commit/7e109d084d55e7eb25837a5f3b47ef9beee547bc ↗
- https://github.com/python/cpython/commit/5181304bcec9cfc3c15311741c9154cdff2e3fd7 ↗
- https://github.com/python/cpython/commit/1e54caa096678a38afcabecabb1ff72400dd6bae ↗
- https://github.com/python/cpython/commit/c016c2535b74227fddf2cf7334dbfead6c930214 ↗
- https://github.com/python/cpython/commit/c28b121a4f0b975937c8b5a1b4934bb361d84296 ↗
- https://github.com/python/cpython/commit/c42790b34f634051750e5da340d17c7da19e4784 ↗
- https://github.com/python/cpython/commit/69f92ebaec681e9149dfd70fd02d4ed52d2a6296 ↗
- https://github.com/python/cpython/commit/d397a4979cfc80a8cd6c73838aa10e9c8cf5ef72 ↗
- http://www.openwall.com/lists/oss-security/2026/08/18/2 ↗