removing "codex --enable use_legacy_landlock" will cause a lot of issues for a lot of people

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• #17337

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hey @user-22-33-56, thanks for the feedback. The main reason we’re moving away from landlock is that Codex needs one Linux sandbox path with more consistent filesystem, namespace, and network behavior across environments. The current direction is bwrap plus seccomp, which gives us a clearer isolation boundary and better fail-closed behavior.

If your host environment can’t run that sandbox directly, a good workaround is to run Codex inside a container and let Docker be the outer security boundary. We have an example devcontainer here:

https://github.com/openai/codex/tree/main/.devcontainer

In VS Code, open the folder in a devcontainer using .devcontainer/devcontainer.secure.json, or from the CLI run:

devcontainer up --workspace-folder . --config .devcontainer/devcontainer.secure.json

Inside the container, you can either keep Codex’s Linux sandbox enabled if the container grants the needed bwrap capabilities, or run Codex with --sandbox danger-full-access if the container itself is the intended isolation boundary.

Currently your default sandbox configuration FAILS on all vanilla ubuntu based systems - you need to fix it or provide clear instructions on how to get bubblewrap working on defauly Ubuntu installation.

DO NOT REMOVE THE LEGACY CONFIG before you have provided documentation and tested yourself how to get your default sandbox working on default Ubuntu installation.

Please refer to this documentation which @viyatb-oai just posted. Let us know if that's helpful or if you have any follow-up questions.

@mikkom-aimbition can you please try this? ubuntu 25.x ships with a profile bwrap-userns-restrict with apparmor-profiles that is somehow not on Ubuntu 24.04 by default - it was removed due to a Flatpak regression. See https://www.ubuntuupdates.org/package/core/noble/main/updates/apparmor-profiles and https://apparmor.net/news/release-4.0.2/

sudo apt update
sudo apt install apparmor-profiles apparmor-utils

dpkg -L apparmor-profiles | grep bwrap-userns-restrict

sudo install -m 0644 \
  /usr/share/apparmor/extra-profiles/bwrap-userns-restrict \
  /etc/apparmor.d/bwrap-userns-restrict

@mikkom-aimbition ^ this fix worked for someone else https://github.com/openai/codex/issues/14936#issuecomment-4296166611.

I've updated the docs to reflect this https://developers.openai.com/codex/concepts/sandboxing#prerequisites - please let me know if its missing anything. Thanks!