{"id":"CVE-2026-64847","title":"AnyIO is a high level asynchronous concurrency and networking framework that works on top of either Trio or asyncio","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,…","severity":"medium","cvss":6.8,"cvssVector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","cwe":["CWE-770","CWE-1322"],"vendor":"agronholm","product":"anyio","affected":["anyio < 4.14.2"],"patched":["anyio 4.14.2"],"published":"2026-09-18","updated":"2026-09-24","sourceUpdated":"2026-09-24T21:25:27.050","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64847","references":[{"url":"https://github.com/agronholm/anyio/commit/f1b7301c8264b0d2e8d24a5788fd29e93dea4040","label":"security-advisories@github.com"},{"url":"https://github.com/agronholm/anyio/pull/1207","label":"security-advisories@github.com"},{"url":"https://github.com/agronholm/anyio/releases/tag/4.14.2","label":"security-advisories@github.com"},{"url":"https://github.com/agronholm/anyio/security/advisories/GHSA-5p39-cfhj-2xmp","label":"security-advisories@github.com"},{"url":"https://github.com/advisories/GHSA-5p39-cfhj-2xmp"},{"url":"https://github.com/agronholm/anyio"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64847.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-64847"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2538074"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64847"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64847"},{"url":"https://access.redhat.com/errata/RHSA-2026:70996"},{"url":"https://access.redhat.com/errata/RHSA-2026:70965"},{"url":"https://access.redhat.com/errata/RHSA-2026:70979"},{"url":"https://access.redhat.com/errata/RHSA-2026:70995"},{"url":"https://access.redhat.com/errata/RHSA-2026:70969"},{"url":"https://access.redhat.com/errata/RHSA-2026:73929"},{"url":"https://access.redhat.com/errata/RHSA-2026:73930"},{"url":"https://pypi.org/project/anyio"}],"tags":["nvd","cve.org","ghsa","pip","osv","csaf","vex","red-hat"],"epss":0.00157,"epssPercentile":0.04757,"aliases":["GHSA-5p39-cfhj-2xmp","PYSEC-2026-4024"],"ecosystem":"pip","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-18T18:07:19.030895Z"},"cvssSource":"cna","scores":{"cna":6.8,"vendor":5.5},"ingestedAt":"2026-09-18T17:46:41.530Z","slug":"CVE-2026-64847","body":"## Overview\n\nAnyIO 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-64847)\n\nAffected packages:\n\n- `anyio < 4.14.2`\n\nPatched in:\n\n- `anyio 4.14.2`\n\nSource: https://github.com/advisories/GHSA-5p39-cfhj-2xmp\n\n## Vendor advisories\n\n- **RHSA-2026:70996** · Red Hat · fixed in: Red Hat AI Inference Server 3.4 · released 2026-09-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:70996)\n- **RHSA-2026:70965** · Red Hat · fixed in: Red Hat AI Inference Server 3.4 · released 2026-09-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:70965)\n- **RHSA-2026:70979** · Red Hat · fixed in: Red Hat AI Inference Server 3.4 · released 2026-09-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:70979)\n- **RHSA-2026:70995** · Red Hat · fixed in: Red Hat AI Inference Server 3.4 · released 2026-09-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:70995)\n- **RHSA-2026:70969** · Red Hat · fixed in: Red Hat AI Inference Server 3.4 · released 2026-09-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:70969)\n- **Red Hat VEX** · Moderate · affected: Ansible Automation Orchestrator 2026, Confidential Compute Attestation, Exploit Intelligence, Lightspeed Core, Migration Toolkit for Applications 8, Migration Toolkit for Containers, … · no fix planned: Exploit Intelligence, Red Hat Ansible Automation Platform 2, Ansible Automation Orchestrator 2026, Confidential Compute Attestation, … · updated 2026-10-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64847.json)\n- **RHSA-2026:73929** · Red Hat · fixed in: Red Hat AI Inference Server 3.2 · released 2026-09-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:73929)\n- **RHSA-2026:73930** · Red Hat · fixed in: Red Hat AI Inference Server 3.2 · released 2026-09-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:73930)","depth":"sunlit","depthScore":37,"depthScoreParts":{"impact":37.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}