# anyio (PyPI) vulnerabilities

3 known vulnerabilities (1 critical, 1 high, 1 medium), with the versions each affects and the releases that fix them.

## At a glance

- Latest release: 4.16.0 (Nov 1, 2026): no advisory affects it
- Newest unaffected release: 4.16.0 (Nov 1, 2026), the latest release
- Weekly downloads: 231.6M
- Releases: 73 since 1.0.0 (May 14, 2019)
- Registry: https://pypi.org/project/anyio/
- Releases read: Nov 8, 2026

## Version timeline

Affected versions per advisory, in version order:

- CVE-2026-63374: 1.0.0a1 to 4.14.1 (4.14.2 is outside it)
- CVE-2026-64847: 1.0.0a1 to 4.14.1 (4.14.2 is outside it)
- CVE-2026-63349: 4.14.0 to 4.14.1 (4.14.2 is outside it)

## Advisories (3)

### [CVE-2026-63374](https://cve.now/CVE-2026-63374): AnyIO: TLSStream IDNA 2003 host name encoding enables potential TLS certificate spoofing

- Severity: Critical 9.3
- Published: Sep 22, 2026
- Affected: fixed in 4.14.2.
- Fixed in 4.14.2 (released Jul 12, 2026, 72 days before disclosure).
- The latest release, 4.16.0, is not affected.

### [CVE-2026-64847](https://cve.now/CVE-2026-64847): AnyIO process-pool workers can block indefinitely on undrained stderr

- Severity: Medium 6.8
- Published: Sep 18, 2026
- Affected: fixed in 4.14.2.
- Fixed in 4.14.2 (released Jul 12, 2026, 68 days before disclosure).
- The latest release, 4.16.0, is not affected.

### [CVE-2026-63349](https://cve.now/CVE-2026-63349): AnyIO run\_process/open\_process ignores extra\_groups and can retain parent supplementary groups

- Severity: High 7.0
- Published: Sep 18, 2026
- Affected: from 4.14.0, fixed in 4.14.2.
- Fixed in 4.14.2 (released Jul 12, 2026, 68 days before disclosure).
- The latest release, 4.16.0, is not affected.

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