CVE-2026-64847

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.

CVSS

No CVSS.

References

Link	Resource
https://github.com/agronholm/anyio/commit/f1b7301c8264b0d2e8d24a5788fd29e93dea4040
https://github.com/agronholm/anyio/pull/1207
https://github.com/agronholm/anyio/releases/tag/4.14.2
https://github.com/agronholm/anyio/security/advisories/GHSA-5p39-cfhj-2xmp

Configurations

No configuration.

History

18 Sep 2026, 18:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-18 18:17

Updated : 2026-09-24 21:25

NVD link : CVE-2026-64847

Mitre link : CVE-2026-64847

CVE.ORG link : CVE-2026-64847

JSON object : View

Products Affected

No product.

CWE

CWE-770

Allocation of Resources Without Limits or Throttling

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