CVE-2026-63349

AnyIO is a high level asynchronous concurrency and networking framework that works on top of either Trio or asyncio. In 4.14.0, AnyIO accepts the POSIX extra_groups argument in anyio.run_process() and anyio.open_process(), but open_process() forwards the group argument to the backend instead of extra_groups. A caller that supplies extra_groups=[] to clear inherited supplementary groups can therefore launch a child that retains the parent process groups, undermining a privilege-dropping boundary. If group is also supplied, the integer group value is passed where an iterable of supplementary groups is expected and the launch can fail with TypeError. This issue affects POSIX applications that rely on AnyIO subprocess helpers to launch less-privileged child processes. This issue is fixed in version 4.14.2.

CVSS

No CVSS.

References

Link	Resource
https://github.com/agronholm/anyio/commit/eb562e6462ee46b1904e50b02ce00a858cdeb200
https://github.com/agronholm/anyio/pull/1209
https://github.com/agronholm/anyio/releases/tag/4.14.2
https://github.com/agronholm/anyio/security/advisories/GHSA-3w57-8xmc-8v26

Configurations

No configuration.

History

18 Sep 2026, 17:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-18 17:16

Updated : 2026-09-25 14:10

NVD link : CVE-2026-63349

Mitre link : CVE-2026-63349

CVE.ORG link : CVE-2026-63349

JSON object : View

Products Affected

No product.

CWE

CWE-266

Incorrect Privilege Assignment

CWE-269

Improper Privilege Management

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