Answer in brief
CVE-2026-63349 records a High severity (CVSS 0.0) vulnerability in AnyIO run_process/open_process ignores extra_groups and can retain parent supplementary groups. The current sources do not mark it as known exploited. The current feed maps agronholm/anyio (generic), anyio (pip), anyio (pypi). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 0.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps agronholm/anyio (generic), anyio (pip), anyio (pypi). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| agronholm/anyiogeneric | >= 4.14.0, < 4.14.2 | Not reported |
| anyiopip | >=4.14.0,<4.14.2 | 4.14.2 |
| anyiopypi | >=4.14.0 <4.14.2 | 4.14.2 |
Published upstream
Sep 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 18, 2026
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.
Quoted source text, attributed separately from HOL analysis.