# CVE-2026-64847: python-anyio: AnyIO is a high level asynchronous concurrency and networking framework that works on top of either Trio or asyncio

CVE-2026-64847 is fixed in python-anyio on 1 platform, first by SUSE-SU-2026:4416-1, released October 2, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-64847
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0016
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 18, 2026

## Description

AnyIO is a high level asynchronous concurrency and networking framework that works on top of either Trio or asyncio. Prior to 4.14.2, AnyIO starts process-pool workers with standard error connected to a pipe that the parent never drains, even though the documented behavior redirects all three standard streams. Worker code that writes enough attacker-influenced data to sys.stderr can fill the pipe and block before returning the standard-output protocol response, causing the awaiting process-pool call to remain blocked indefinitely. Applications that run untrusted or faulty worker code capable of producing substantial standard-error output are affected. This issue is fixed in version 4.14.2.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-anyio Debian 14 | 4.15.1-1 | [DEBIAN-CVE-2026-64847](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64847.md) | Oct 6, 2026 |
| Linux | python-anyio opensuse-leap 16.0 | 4.8.0-160000.3.1 | [OPENSUSE-SU-2026:22060-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22060-1.md) | Nov 7, 2026 |
| Linux | python-anyio sles 15.6 | 4.1.0-150400.9.11.1 | [SUSE-SU-2026:4416-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4416-1.md) | Oct 2, 2026 |
| Linux | python-anyio sles 15.7 | 4.1.0-150400.9.11.1 | [SUSE-SU-2026:4416-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4416-1.md) | Oct 2, 2026 |
| Linux | python-anyio sles 16.0 | 4.8.0-160000.3.1 | [SUSE-SU-2026:24208-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24208-1.md) | Nov 7, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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