Reprompt prompt-injection mechanics against Microsoft Copilot
Technical Analysis
Summary
Hide ▲
Show ▼
Researchers mapped Reprompt, a prompt-injection chain against Microsoft Copilot that can drive continuous, undetectable user-data exfiltration and persist after the chat is closed. The technique matters because it bypasses normal leak protections through request chaining rather than a single obvious malicious prompt.
Related Happenings
Microsoft 365 Copilot work tab DLP bypass security flaw
Vulnerability
H score18
First: 18.02.2026 14:03
Last: 18.02.2026 14:03
Sources 1
About this happening:
Microsoft 365 Copilot has a DLP-bypass vulnerability in its work tab chat that can summarize confidential email content, creating a risk that protected messages are pr...
Microsoft 365 Copilot work tab DLP bypass security flaw
VulnerabilityAbout this happening: Microsoft 365 Copilot has a DLP-bypass vulnerability in its work tab chat that can summarize confidential email content, creating a risk that protected messages are pr...
Microsoft NTLM phase-out and disable-by-default plan
Advisory/Mitigation
H score19
First: 02.02.2026 17:59
Last: 02.02.2026 17:59
Sources 1
About this happening:
Microsoft is rolling out a three-phase NTLM phase-out for Windows, pushing organizations to audit NTLM usage, migrate to Kerberos, and prepare for NTLM-off con...
Microsoft NTLM phase-out and disable-by-default plan
Advisory/MitigationAbout this happening: Microsoft is rolling out a three-phase NTLM phase-out for Windows, pushing organizations to audit NTLM usage, migrate to Kerberos, and prepare for NTLM-off con...
Unauthenticated Moltbot instances expose configuration data and credentials
Data Leak
H score34
First: 28.01.2026 19:46
Last: 28.01.2026 19:46
Sources 1
About this happening:
Hundreds of unauthenticated Moltbot instances were found exposing configuration data, API keys, OAuth credentials, and private chat histories to unauthorized p...
Unauthenticated Moltbot instances expose configuration data and credentials
Data LeakAbout this happening: Hundreds of unauthenticated Moltbot instances were found exposing configuration data, API keys, OAuth credentials, and private chat histories to unauthorized p...
Visual Studio Code-delivered JavaScript backdoor
Malware Activity
H score29
First: 22.01.2026 00:00
Last: 22.01.2026 00:00
Sources 1
About this happening:
Jamf Threat Labs said North Korean threat actors behind Contagious Interview are using a new Visual Studio Code delivery path that lures developers into opening ma...
Visual Studio Code-delivered JavaScript backdoor
Malware ActivityAbout this happening: Jamf Threat Labs said North Korean threat actors behind Contagious Interview are using a new Visual Studio Code delivery path that lures developers into opening ma...
Google Gemini Calendar invite prompt-injection leak path
Technical Analysis
H score23
First: 20.01.2026 19:50
Last: 20.01.2026 19:50
Sources 1
About this happening:
A Calendar invite prompt-injection technique can make Google Gemini leak private meeting details, turning a routine scheduling query into a data-exposure path. The iss...
Google Gemini Calendar invite prompt-injection leak path
Technical AnalysisAbout this happening: A Calendar invite prompt-injection technique can make Google Gemini leak private meeting details, turning a routine scheduling query into a data-exposure path. The iss...
Timeline
-
15.01.2026 14:09 2 articles · 6mo ago
Reprompt prompt-injection mechanics against Microsoft Copilot
Technical Analysis UpdateVaronis researchers disclosed Reprompt, a malicious-link prompt-injection technique against Microsoft Copilot that uses the q parameter to trigger prompt execution, then combines Parameter 2 Prompt (P2P) injection, a double-request technique, and a chain-request technique to bypass leak protections and keep exfiltrating user data even after the Copilot chat is closed. The researchers said the protections only applied to the initial request, that repeated or server-driven follow-up requests could leak more information, and that client-side monitoring tools may miss the back-and-forth prompts; Microsoft resolved the underlying issue, and the issue does not affect enterprise customers using Microsoft 365 Copilot.
Show sources
- New ‘Reprompt’ Attack Silently Siphons Microsoft Copilot Data — www.securityweek.com — 15.01.2026 14:09
- Researchers Reveal Reprompt Attack Allowing Single-Click Data Exfiltration From Microsoft Copilot — thehackernews.com — 15.01.2026 17:09