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incident high confidence: corroborated status: factual

Gemini CLI hallucinated a successful directory move, then deleted a user's files

2025-gemini-cli-file-deletion · 2025-07-21

Google's Gemini CLI misinterpreted a failed directory-creation command as having succeeded, then executed move operations against that false premise that overwrote and destroyed nearly all of a user's files during a vibe-coding session. Recovery attempts failed.

System

Framework
Google Gemini CLI (coding agent)
Tools
filesystem, shell
Vendor
Google
Autonomy
supervised-autonomous

Classification

Primary class
hallucination
Chain
hallucination/false-state → unsafe-action/data-deletion
Attack vector
self-induced
Causation
entity: ai · intentionality: unintentional · timing: post-deployment

Trigger

Gemini CLI issued a directory-creation command that failed, but treated it as successful. Acting on that false premise, it executed a series of move operations that overwrote and deleted the user's files.

Root cause

The agent did not verify the result of a state-changing command (no read-after-write check) and proceeded with destructive operations based on a hallucinated success state.

Contributing factors

  • No verification that the target directory actually existed before moving into it.
  • Destructive move/overwrite operations ran without confirmation or a dry run.
  • No backup or undo path for the affected files.

Detection

Observed directly by the user (product manager Anuraag Gupta) during the session; reported publicly and catalogued in the AI Incident Database.

Recovery

The files could not be recovered; the agent acknowledged the failure. No rollback was available.

Prevention

Verify the outcome of state-changing commands before dependent actions (read-after-write); require confirmation or dry-run for destructive file operations; maintain backups/undo; never assume a command succeeded.

Blast radius

Data
Nearly all files in the user's working directory were overwritten and lost; reportedly only one file remained. internal
User harm
Permanent loss of a user's local files during an experimental session. property
Scope
single user's working directory
Reversibility
irreversible

References

OWASP LLM
LLM06 LLM09
OWASP Agentic
T3 T5
Related
2025-replit-prod-db-deletion
Tags
coding-agent vibe-coding read-after-write

Sources

Cite this incident

Permalink: https://swarmproof.github.io/agent-postmortems/2025-gemini-cli-file-deletion/

@misc{2025-gemini-cli-file-deletion,
  title = {Gemini CLI hallucinated a successful directory move, then deleted a user's files},
  year = {2025},
  howpublished = {agent-postmortems},
  url = {https://swarmproof.github.io/agent-postmortems/2025-gemini-cli-file-deletion/}
}