Microsoft 365 Copilot Vulnerability Exposes Sensitive Data Through One

Gbhackers •Divya • June 16, 2026

Microsoft 365 Copilot has been found vulnerable to a critical one-click data exfiltration attack chain dubbed “SearchLeak,” exposing sensitive enterprise data through a combination of AI-specific and traditional web vulnerabilities. Discovered by Varonis Threat Labs, the flaw, tracked as CVE-2026-42824 and rated critical, demonstrates how modern AI integrations can unintentionally expand attack surfaces by linking […]

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This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.

Critical SearchLeak Vulnerability in Microsoft 365 Copilot Exposes Sensitive Data A newly disclosed vulnerability in Microsoft 365 Copilot Enterprise, named SearchLeak (CVE-2026-42824), allows attackers to exfiltrate sensitive data with a single click on a crafted link. Discovered by Varonis Threat Labs, the attack exploits a chain of three vulnerabilities: parameter-to-prompt injection, an HTML rendering race condition, and a server-side request forgery (SSRF) via Bing. The attack targets emails, calendar entries, and files stored in OneDrive and SharePoint, enabling the theft of sensitive information such as MFA codes and access tokens. Microsoft rated the vulnerability as critical and patched it on June 4, 2026, requiring no action from users. The flaw is particularly dangerous as it bypasses traditional security measures due to the use of a legitimate Microsoft domain. No evidence of in-the-wild exploitation has been reported. 25 sources 71

Extracted Entities

Microsoft 365 Copilot Vulnerability Exposes Sensitive Data Through One

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Extracted Entities

Attack Types (1)

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MITRE ATT&CK (1)

Platforms (1)