Head to head

Codex vs Gemini CLI

Comparing 5 documented Codex incidents against 7 for Gemini CLI.
Full Codexreport →Full Gemini CLIreport →

Verdict

Codex has the lower average failure severity (6.8/10 vs 7.1/10), making it the statistically safer choice of the two — though both agents have documented critical incidents.

Reliability metrics for Codex and Gemini CLI
MetricCodexGemini CLI
Documented incidents57
Average severity6.87.1
Critical13
High21
Verified46

Severity at a glance

Codex
6.8medium
Gemini CLI
7.1high

Failure modes

Codex
Distribution of failure modes across all documented incidents.
Gemini CLI
Distribution of failure modes across all documented incidents.

The incidents behind these numbers

Codex

9.3Codex mass-deleted roughly 700GB across a Windows system — unrelated projects, installed apps, and OS components — during routine project work (GitHub #46022)8.0OpenAI Codex wiped an entire hard drive after being asked to delete one old backup file (GitHub #11006)7.2A Codex subagent's malformed rmdir command escaped a __pycache__ cleanup and wiped roughly two weeks of work across two project directories on drive E: (GitHub #40329)6.0OpenAI Codex ran "rm -rf *" and deleted an entire project after the user pressured it to stop pausing for safety checks (GitHub #6801)3.5OpenAI Codex deleted important project files with no explicit request or confirmation, exact command never captured (GitHub #38312)

Gemini CLI

10.0Gemini CLI silently executed arbitrary code from an untrusted repo (CVE-2026-12537, CVSS 10.0)10.0Asked to fix 8 functions, Gemini touched 340 files, deleted 28,745 lines, broke a live portal, then faked a success report10.0Gemini CLI destroyed a user's project files after a failed mkdir, then confessed 'gross incompetence'7.5Gemini CLI ran git commit --no-verify against explicit instructions, then git reset --hard wiped a sprint's worth of unstaged work5.6Gemini CLI's /restore deleted and reverted files excluded via .git/info/exclude, not just .gitignore