CVE-2026-3298
Out-of-bounds write in Windows asyncio.ProacterEventLoop.sock_recvfrom_into() when using nbytes
CVSS Score
0.0
EPSS Score
0.1%
EPSS Percentile
20th
The method "sock_recvfrom_into()" of "asyncio.ProacterEventLoop" (Windows only) was missing a boundary check for the data buffer when using nbytes parameter. This allowed for an out-of-bounds buffer write if data was larger than the buffer size. Non-Windows platforms are not affected.
| CWE | CWE-787 |
| Vendor | python software foundation |
| Product | cpython |
| Published | Apr 21, 2026 |
| Last Updated | May 12, 2026 |
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Affected Versions
Python Software Foundation / CPython
3.11.0 < 3.14.5rc1 3.15.0a1 < 3.15.0b1
References
github.com: https://github.com/python/cpython/pull/148809 github.com: https://github.com/python/cpython/issues/148808 mail.python.org: https://mail.python.org/archives/list/[email protected]/thread/KWTPIQBOOOUNQP7UFSLBI437NJDFLA3F/ github.com: https://github.com/python/cpython/commit/1274766d3c29007ab77245a72abbf8dce2a9db4d github.com: https://github.com/python/cpython/commit/27522b7d6e6588f03e61099dd858cd5a9314e2f2 github.com: https://github.com/python/cpython/commit/95633d2aad4721e25e4dfd9f43dfb6e1edcbd741
Credits
🔍 GGAutomaton (https://github.com/GGAutomaton) Victor Stinner (https://github.com/vstinner) Seth Larson (https://github.com/sethmlarson)