I ran my scanner against 5 real CVEs. It missed 4. Then I reverted my own fix.

Why this post is different from the last one The last write-up in this series announced four tools. This one is about what happened when I stopped writing tests for my own tools and started checking one of them against reality — and about the fix I built, tested, shipped, and then took back out, because it was wrong in a way that only showed up once I looked past the headline number. The setup: inlet, and the claim it hadn't actually tested inlet is a static scanner: point it at a Python codebase, it finds every call site that looks like SQL execution — raw DB API calls, Django's .raw()/.extra(), SQLAlchemy's text() — and classifies each as parameterized, concatenated, or uncertain. Every claim in its original README was backed by 7 hand-written fixtures, each proving one specific classification rule. That's real, but it's not evidence of anything beyond "the mechanism works on cases designed to exercise it." So I built a real-world evaluation: 15 PyPI packages, split into two groups. Group A (5 packages): each with a documented, independently verified historical SQL-injection CVE, with the fix commit or advisory located ahead of time so I could check inlet's output against ground truth, not against inlet's own opinion of itself. Group B (10 packages): popular, no known SQLi history — a noise-floor check on how often inlet flags something that isn't actually a risk. ~772K lines of real code, scanned unmodified, in about 10.6 seconds combined. The result: 0 for 5 Django (CVE-2022-28346), Apache Superset (CVE-2023-49736), Tortoise ORM (CVE-2020-11010), and Airflow's common-sql provider (CVE-2025-30473) were all complete misses. Archery's CVE-2023-30556 was a partial — the exact vulnerable line showed up in inlet's output, but classified uncertain instead of concatenated, because the f-string assignment sat inside a try: block, a name-resolution gap beyond the documented scope wall. The pattern behind all four full misses was identical: the vulnerable code never litera