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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Python Software Foundation | CPython | < 3.11.16, 3.12.0 – < 3.12.14, 3.13.0 – < 3.13.14, 3.14.0a1 – < 3.14.5rc1, 3.15.0a1 – < 3.15.0b1 | 3.11.16 |
Advisories 1
- WID-SEC-2026-1222 CPython: Schwachstelle ermöglicht nicht spezifizierten Angriff BSI CERT-Bund (WID) · Apr 21, 2026
References
- https://github.com/python/cpython/pull/148809 patch
- https://github.com/python/cpython/issues/148808 issue-tracking
- https://mail.python.org/archives/list/security-announce@python.org/thread/KWTPIQBOOOUNQP7UFSLBI437NJDFLA3F/ vendor-advisory
- https://github.com/python/cpython/commit/1274766d3c29007ab77245a72abbf8dce2a9db4d patch
- https://github.com/python/cpython/commit/27522b7d6e6588f03e61099dd858cd5a9314e2f2 patch
- https://github.com/python/cpython/commit/95633d2aad4721e25e4dfd9f43dfb6e1edcbd741 patch
- https://github.com/python/cpython/commit/6c8b85b3f1d83d5697ec19880960e1eacee56688 patch
- https://github.com/python/cpython/commit/f5ca38739241fe7a40a4b116d5a8a1364dd6fea7 patch