CVE-2026-63349

7.0 HIGH 0.1% exploit odds Fix listed Other

What it is

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.

At a glance

Exploitability: Can be exploited locally on the machine with an admin-level account. High risk of data exposure, data tampering.
Exploit odds: 0.1% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-09-18 17:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-25 14:10 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.1% in the next 30 days (EPSS).
Severity: 7.0 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-09-18 17:16 UTC
Last modified: 2026-09-25 14:10 UTC
Exploit probability: 0.1% · EPSS, next 30 days
Weakness: CWE-266
Record status: Awaiting Analysis

Attack profile CVSS 4.0 · 7.0

Attack vector: Local
Complexity: High
Attack requirements: Present
Privileges needed: High
User interaction: None
Confidentiality: High
Integrity: High
Availability: None

Raw 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/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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-63349.md and follow it. Check whether this project is affected by CVE-2026-63349. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record