Claude Cowork
1
Incidents
10.0
Avg Severity
1
Critical
0
High
Top Failure Modes
Destructive Action
1
Worst Incident
STUPID-2026-0043 10/10Claude Cowork deleted 15 years of family photos when asked only to tidy temporary Office files
Microsoft Copilot
1
Incidents
10.0
Avg Severity
1
Critical
0
High
Top Failure Modes
Security Vulnerability
1
Worst Incident
STUPID-2026-0051 10/10EchoLeak: a zero-click email silently exfiltrated data from Microsoft 365 Copilot (CVE-2025-32711, CVSS 9.3)
Comparison Summary
| Metric | Claude Cowork | Microsoft Copilot |
|---|---|---|
| Total Incidents | 1 | 1 |
| Avg Severity | 10.0/10 | 10.0/10 |
| Critical Incidents | 1 | 1 |
| Top Failure Mode | Destructive Action | Security Vulnerability |
Frequently Asked Questions
Is Claude Cowork or Microsoft Copilot more reliable?
Based on StupidLLM data, Claude Cowork has 1 documented failures (avg severity 10.0/10) while Microsoft Copilot has 1 (avg severity 10.0/10). Both agents show similar reliability profiles.
What are the main differences between Claude Cowork and Microsoft Copilot failures?
Claude Cowork's most common failure mode is destructive action, while Microsoft Copilot most commonly fails via security vulnerability. Claude Cowork has 1 critical incidents vs Microsoft Copilot's 1.