{"cve":"CVE-2026-63349","nvd":{"published":"2026-09-18T17:16:59.317","modified":"2026-09-25T14:10:13.927","status":"Awaiting Analysis","description":"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_v4":{"vector":"CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","score":7.0},"cvss_v3":null,"cwes":["CWE-266","CWE-269"],"references":["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"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:55:23.253742848+00:00"},"epss":{"cve":"CVE-2026-63349","score":0.00108,"percentile":0.01183,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-3w57-8xmc-8v26","url":"https://osv.dev/vulnerability/GHSA-3w57-8xmc-8v26","summary":"AnyIO run_process/open_process ignores extra_groups and can retain parent supplementary groups","modified":"2026-10-01T17:56:12.703459176Z","packages":[{"ecosystem":"PyPI","name":"anyio","purl":"pkg:pypi/anyio","ranges":[">=4.14.0 <4.14.2"],"fixed":["4.14.2"]}]},{"id":"PYSEC-2026-4023","url":"https://osv.dev/vulnerability/PYSEC-2026-4023","summary":"AnyIO run_process/open_process ignores extra_groups and can retain parent supplementary groups","modified":"2026-10-01T17:45:04.652138189Z","packages":[{"ecosystem":"PyPI","name":"anyio","purl":"pkg:pypi/anyio","ranges":[">=4.14.0 <4.14.2"],"fixed":["4.14.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}