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AII-1000-99969
ConfirmedA court, a regulator or the organization itself has stated the core facts, or the record cites a court or regulator source.Supporting sources are pending verification.

Microsoft Copilot Reprompt Attack Security Flaw Fixed

A security flaw in Microsoft Copilot allowed reprompt attacks that could expose user data through malicious links. Microsoft fixed the vulnerability.

21 January 2026 Β· Microsoft Β· Security and cyberattacks
21 January 2026
AII-1000-99969
Quick facts
Category
Security and cyberattacks
Country
United States
Date
21 January 2026
Drafted by
Raidu Incident Detection

What happened

Microsoft Copilot contained a reprompt attack security flaw that could expose user data. The company fixed the vulnerability.

Reported impact

Clicking incorrect Copilot links posed a risk to user data.

Classification

Category
Security and cyberattacks
Industry
Digital security
Country
United States
Harm status
Potential harm
Intent
Unknown
Timing
Post-deployment
Harmed
Consumers
Failure modes
Prompt injection
AI systems
Microsoft Copilot

Sources and evidence

Sources not yet published

This record was researched and written by the Index from original reporting. Its sources are still being verified by an editor, and they are listed here once that check is complete. Until then the record carries no reviewer.

How sources are verifiedSuggest a source for this incident