CVE-2026-3298CWE-787

CVE-2026-3298

published April 21, 2026

CVSS
8.8
EPSS
1%
Percentile
48.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS
8.8 · NONE
CVSS v4.0
Not supplied
EPSS
0.00604 · 48.2th percentile
Weakness
CWE-787 · Out-of-bounds Write
Published
2026-04-21T19:16Z
References (8)
https://github.com/python/cpython/commit/1274766d3c29007ab77245a72abbf8dce2a9db4d · [email protected]https://github.com/python/cpython/commit/27522b7d6e6588f03e61099dd858cd5a9314e2f2 · [email protected]https://github.com/python/cpython/commit/6c8b85b3f1d83d5697ec19880960e1eacee56688 · [email protected]https://github.com/python/cpython/commit/95633d2aad4721e25e4dfd9f43dfb6e1edcbd741 · [email protected]https://github.com/python/cpython/commit/f5ca38739241fe7a40a4b116d5a8a1364dd6fea7 · [email protected]https://github.com/python/cpython/issues/148808 · [email protected]https://github.com/python/cpython/pull/148809 · [email protected]https://mail.python.org/archives/list/[email protected]/thread/KWTPIQBOOOUNQP7UFSLBI437NJDFLA3F/ · [email protected]
EPSS history
Timeline
  • 21 APR 14:45Z
    Out-of-bounds write in Windows asyncio.ProacterEventLoop.sock_recvfrom_into() when using nbytes
    cvelistv5