CVE-2026-3298
Severity CVSS v4.0:
HIGH
Type:
CWE-787
Out-of-bounds Write
Publication date:
21/04/2026
Last modified:
21/04/2026
Description
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.
Impact
Base Score 4.0
8.80
Severity 4.0
HIGH
References to Advisories, Solutions, and Tools
- https://github.com/python/cpython/commit/1274766d3c29007ab77245a72abbf8dce2a9db4d
- https://github.com/python/cpython/commit/27522b7d6e6588f03e61099dd858cd5a9314e2f2
- https://github.com/python/cpython/commit/95633d2aad4721e25e4dfd9f43dfb6e1edcbd741
- https://github.com/python/cpython/issues/148808
- https://github.com/python/cpython/pull/148809
- https://mail.python.org/archives/list/security-announce@python.org/thread/KWTPIQBOOOUNQP7UFSLBI437NJDFLA3F/



