{"id":"DEBIAN-CVE-2026-64847","details":"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.","modified":"2026-09-25T09:00:35.441702793Z","published":"2026-09-18T18:17:10.930Z","upstream":["CVE-2026-64847"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-64847"}],"affected":[{"package":{"name":"python-anyio","ecosystem":"Debian:12","purl":"pkg:deb/debian/python-anyio?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.6.2-1","3.7.0-1","4.1.0-1","4.11.0-1","4.11.0-2","4.11.0-3","4.12.1-1","4.12.1-2","4.12.1-3","4.15.1-1","4.2.0-1","4.3.0-1","4.4.0-1","4.6.0-1","4.6.2-1","4.6.2-2","4.6.2-3","4.6.2-4","4.7.0-1","4.8.0-1","4.8.0-2","4.8.0-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-64847.json"}},{"package":{"name":"python-anyio","ecosystem":"Debian:13","purl":"pkg:deb/debian/python-anyio?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.11.0-1","4.11.0-2","4.11.0-3","4.12.1-1","4.12.1-2","4.12.1-3","4.15.1-1","4.8.0-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-64847.json"}},{"package":{"name":"python-anyio","ecosystem":"Debian:14","purl":"pkg:deb/debian/python-anyio?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.11.0-1","4.11.0-2","4.11.0-3","4.12.1-1","4.12.1-2","4.12.1-3","4.15.1-1","4.8.0-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-64847.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}