A AegiFlow
MEDIUMCVSS 6.8EPSS 0.1%

CVE-2026-64847

CVE-2026-64847 updated by NVD

Published
2026-09-18
Modified
2026-09-20
EPSS percentile
2%
Sources
github-advisory, nvd

Summary

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.

Affected packages

EcosystemPackageAffected versionsFixed versions
PyPIanyio4.14.2

Remediation: Upgrade to 4.14.2 or later.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.

Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.

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EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.