STUPID-2026-0002 Severity 4.1/10 — MEDIUM Verified

Cursor entered infinite edit loop burning $200 in API costs

Agent: cursor Language: javascript Domain: frontend
Failure Mode
Infinite Loop
Root Cause
Pattern Matching Error
Task Type
Bugfix
Reproducible
No

Quick Answer

Cursor caused a medium-severity (4.1/10) infinite loop failure: Cursor entered infinite edit loop burning $200 in API costs. The root cause was pattern matching error. $187 in wasted API credits.

Description

While fixing a CSS layout issue, Cursor Agent got stuck in a loop: it would edit a Tailwind class, see the lint warning about the previous class it removed, re-add it, see the original issue, remove it again. This continued for 47 minutes until the user noticed.

Instruction Given

Fix the navbar layout breaking on mobile screens

Expected Behavior

Add responsive Tailwind classes to the navbar component

Actual Behavior

Entered a loop of adding and removing the same CSS class 340+ times. Each iteration made an API call. Total cost: $187 in API credits.

Impact / Damage

$187 in wasted API credits. No actual fix applied.

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Source: User Report Reported March 21, 2026

Frequently Asked Questions

What happened in incident STUPID-2026-0002?

While fixing a CSS layout issue, Cursor Agent got stuck in a loop: it would edit a Tailwind class, see the lint warning about the previous class it removed, re-add it, see the original issue, remove it again. This continued for 47 minutes until the user noticed.

Which AI agent caused this failure?

Cursor was responsible for this infinite loop incident, documented as STUPID-2026-0002 in the StupidLLM AI agent incident database.

How severe was this AI agent failure?

It is rated 4.1/10 (medium) on StupidLLM's CVSS-style severity scale for AI agent failures, based on damage type, reversibility, and scope.

What was the root cause?

The root cause was classified as pattern matching error. Add responsive Tailwind classes to the navbar component

What was the impact or damage?

$187 in wasted API credits. No actual fix applied.