Codex has sandbox bypass due to bug in path configuration logic

Due to a bug in the sandbox configuration logic, Codex CLI could treat a model-generated `cwd` as the sandbox’s writable root, including paths outside of the folder where the user started their session. This logic bypassed the intended workspace boundary and enables arbitrary file writes and command execution where the Codex process has permissions - this did not impact the network-disabled sandbox restriction. **Remediation** We released a patch in Codex CLI **0.39.0** that canonicalizes and validates that the boundary used for sandbox policy is based on where the user started the session, and not the one generated by the model. Users running 0.38.0 or earlier should update immediately via their package manager or by reinstalling the latest Codex CLI to ensure sandbox boundaries are enforced. If using the Codex IDE extension, users should immediately update to **0.4.12** for a fix of the sandbox issue. Thank you to Tzanko Matev (Codetracer) for reporting the issue!

Source published

19 Sep 2025 17:14:04 UTC

Source modified

22 Sep 2025 21:59:01 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Publisher rating · HIGH