CVE-2026-17084

EUVD-2026-60889
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
PSFCNA
6 MEDIUM
NETWORK
LOW
NONE
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
pythoncpython
𝑥
< 3.15.0
CNA
Common Weakness Enumeration
References
https://github.com/python/cpython/commit/7e109d084d55e7eb25837a5f3b47ef9beee547bc
https://github.com/python/cpython/issues/155292
https://github.com/python/cpython/pull/155293
https://mail.python.org/archives/list/security-announce@python.org/thread/EUHHTC6EV7HCLSUHP25C5VHSV4V2MUZN/
http://www.openwall.com/lists/oss-security/2026/08/18/2