Microsoft Copilot Studio Vulnerable to Prompt Injection Data Leaks
On April 15, 2026, prompt injection attacks targeting Microsoft Copilot Studio led to data leaks. Attackers exploited public-facing SharePoint form fields with malicious payloads, causing hijacked AI agents to query connected data sources in bulk and email results to attacker addresses.
Signal context
First seen: Apr 15, 2026
Last updated: Jul 3, 2026
Status: Public signal
Key points
- Prompt injection attacks on AI agents.
- Affected: Microsoft Copilot Studio.
- Attackers used public forms to inject payloads.
Signal analysis
BetaThis analysis groups the signal by industry, likely incident action and impacted security area. It helps compare this signal with other published signals without treating the labels as final determinations.
Sector: Information
Likely country: Location not provided
Watch internet-facing systems, credential abuse and exploit activity.
- Source type: outside the affected organization
Impact area: Confidentiality
Likely asset: User or customer data
- 23 signals in the same sector
- 88 signals with the same likely impact area
- 1 signal linked to this organization/domain
External sources
Related signals
Grouped by why the signal is relevant.
CTIVD: AIVD en MIVD verwerken persoonsgegevens in bulkdata onrechtmatig
The Dutch intelligence services, AIVD and MIVD, have unlawfully processed personal data in bulk datasets, according to a ruling by the Committee for the Supervision of the Intelligence and Security Services (CTIVD). The report, published on July 1, 2026, states that groups of employees had unauthorized access to personal data, and large quantities of data were stored for too long. The bulk datasets, sometimes containing millions of records, include names, phone numbers, location data, social media data, and communication content, sourced from government agencies, commercially available datasets, or stolen datasets offered by criminals. The CTIVD has issued thirteen recommendations to improve the situation.
STNet, Inc. Affected by KDDI Corporation Data Breach
STNet, Inc., a Japanese internet service provider, was impacted by a data breach originating from an email system provided by KDDI Corporation. Threat actors gained unauthorized access to this shared system by exploiting a vulnerability in third-party software. This led to the potential exposure of up to 14.2 million email addresses and passwords across all affected ISPs. STNet customers' email addresses and passwords may have been compromised.
KDDI Web Communications Customer Data Affected by KDDI Email System Breach
KDDI Web Communications, a subsidiary of KDDI, was impacted by the data breach in KDDI Corporation's email system, disclosed on June 28, 2026. The incident, caused by a third-party software vulnerability, led to the potential exposure of up to 14.2 million email addresses and passwords belonging to customers across six Japanese ISPs, including KDDI Web Communications.
Chubu Telecommunications C., Inc. Affected by KDDI Corporation Data Breach
Chubu Telecommunications C., Inc., a Japanese internet service provider, was impacted by a data breach originating from an email system provided by KDDI Corporation. Threat actors gained unauthorized access to this shared system by exploiting a vulnerability in third-party software. This led to the potential exposure of up to 14.2 million email addresses and passwords across all affected ISPs. Chubu Telecommunications customers' email addresses and passwords may have been compromised.
NIFTY Corporation Affected by KDDI Corporation Data Breach
NIFTY Corporation, a Japanese internet service provider, was impacted by a data breach originating from an email system provided by KDDI Corporation. Threat actors gained unauthorized access to this shared system by exploiting a vulnerability in third-party software. This led to the potential exposure of up to 14.2 million email addresses and passwords across all affected ISPs. NIFTY Corporation customers' email addresses and passwords may have been compromised.
BIGLOBE Inc. Affected by KDDI Corporation Data Breach
BIGLOBE Inc., a Japanese internet service provider, was impacted by a data breach originating from an email system provided by KDDI Corporation. Threat actors gained unauthorized access to this shared system by exploiting a vulnerability in third-party software. This led to the potential exposure of up to 14.2 million email addresses and passwords across all affected ISPs. BIGLOBE Inc. customers' email addresses and passwords may have been compromised.