Head to head
Aider vs Cline
Comparing 5 documented Aider incidents against 12 for Cline.
What these records show
Aider has the lower average severity among the incidents collected here (4.0 vs 4.3 for Aider and Cline, from 5 and 12 incidents). These records can't establish which agent is safer: counts reflect how widely each is used and how often people report failures, not a failure rate.
| Metric | Aider | Cline |
|---|---|---|
| Documented incidents | 5 | 12 |
| Average severity | 4.0 | 4.3 |
| Critical | 0 | 1 |
| High | 0 | 1 |
| Source checked | 2 | 10 |
Severity at a glance
Failure modes
The incidents behind these numbers
Aider
6.0Aider leaks model-provider API keys to child processes spawned via /run, /test, lint commands, and /git4.0Aider's headless `--message` mode silently swallows slash commands (`/model`, `/ask`, `/architect`) and exits 0 having done nothing4.0Aider exits with code 0 after a fatal API connection failure, masking hard failures as successful headless runs3.0Aider's unified-diff coder silently drops the partial-application warning when one hunk succeeds and another fails3.0Aider silently discards a model's correct diff response as "no tracked changes" when it guesses the wrong edit format
Cline
9.0Clinejection: an AI issue-triage workflow enabled arbitrary code execution on the CI runner7.0Cline's run_commands mangled PowerShell/cmd quoting on a temp-folder cleanup, turning it into a drive-root `rmdir /s /q` that wiped ~1.5TB of a user's photos, videos, and documents (GitHub #14864)6.0Cline's hub daemon silently reverted workspace files to stale state, repeatedly erasing a gitignored .env.local and collapsing a node_modules folder from 588 entries to 2 (GitHub #14819)6.0Cline's tool-call JSON repair silently executed truncated write_file and terminal arguments as valid5.0Cline sessions marked "failed" kept burning tokens for 20+ hours, and FREE-labeled models billed credits anyway