Out-of-bounds write in Windows asyncio.ProacterEventLoop.sock_recvfrom_into() when using nbytes
CVE-2026-3298 is fixed in 2 products on 2 platforms, first by Python 3.14 3.14.5, released May 10, 2026. 10 other affected products have no fix yet. It is not reported as exploited. Patch Radar priority: High.
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.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Windows apps | |||
| Python 3.13 | 3.13.14 | Python 3.13 3.13.14 | Jun 10, 2026 |
| Python 3.14 | 3.14.5 | Python 3.14 3.14.5 | May 10, 2026 |
| No fix yet | |||
| Python 2 (Windows apps) | No fix yet | no-fix | n/a |
| Python 3.10 (Windows apps) | No fix yet | no-fix | n/a |
| Python 3.11 (Windows apps) | No fix yet | no-fix | n/a |
| Python 3.12 (Windows apps) | No fix yet | no-fix | n/a |
| Python 3.5 (Windows apps) | No fix yet | no-fix | n/a |
| Python 3.6 (Windows apps) | No fix yet | no-fix | n/a |
| Python 3.7 (Windows apps) | No fix yet | no-fix | n/a |
| Python 3.8 (Windows apps) | No fix yet | no-fix | n/a |
| Python 3.9 (Windows apps) | No fix yet | no-fix | n/a |
| Python3 (macOS) | No fix yet | no-fix | n/a |
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