Critical Microsoft 365 Copilot Vulnerability Allows Attackers to Steal Data in One Click

Cybersecuritynews •Guru Baran • June 15, 2026

A critical vulnerability chain in Microsoft 365 Copilot Enterprise that let attackers steal sensitive corporate data, MFA codes, email contents, calendar details, and confidential files with nothing more than a single click on a link pointing to a legitimate Microsoft domain. Dubbed SearchLeak, uncovered by Varonis Threat Labs and tracked as CVE-2026-42824, the flaw earned […]

The full story

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. 34 sources 71

Extracted Entities

Critical Microsoft 365 Copilot Vulnerability Allows Attackers to Steal Data in One Click

The full story

Extracted Entities

Attack Types (1)

CVEs (1)

MITRE ATT&CK (1)

Platforms (1)

Vulnerabilities (1)