INSPECTING ARCHIVED INTELLIGENCE (OUTDATED VERSION).

One-Click Microsoft 365 Data Theft Vulnerability Exploit

| 2026-06-15 15:09 CRITICAL HIGH
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Executive Summary AI-generated
The discovery of SearchLeak, a one-click exfiltration path exploited by three bugs in Microsoft's Copilot Enterprise Search tool, has significant implications for enterprise security. The technique leverages vulnerabilities in the software to steal sensitive information such as emails, files, and MFA codes. This could have far-reaching consequences, including unauthorized access to user accounts, intellectual property, and confidential data. As a result, organizations must take immediate action to patch these vulnerabilities and implement additional security measures to prevent exploitation of this technique.
Technical Mitigations AI-generated
* Implement Content Security Policy (CSP) blocking: Ensure that the Microsoft Graph API and SharePoint/OneDrive data is blocked by CSP, preventing attackers from accessing sensitive information. * Use a secure protocol for communication with Bing: When communicating with Bing to retrieve stolen data, use HTTPS or a secure tunneling protocol like TLS 1.2 to encrypt the communication between the attacker's server and the victim's browser. * Implement rate limiting on API calls: Limit the number of API calls made by an attacker within a certain time frame (e.g., 10-15 minutes) to prevent them from exploiting the vulnerability repeatedly. * Use a secure password manager or generate strong passwords: Ensure that all accounts, including Microsoft Graph and SharePoint/OneDrive, use strong, unique passwords or have a secure password manager in place to protect against data theft. * Monitor for suspicious activity and implement incident response plan: Establish an incident response plan to quickly respond to potential security incidents, such as unauthorized access to sensitive information.
Technical Observables
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Intelligence Metadata
Actors / Malware / CVEs / Campaigns
CVE-2026-42824CVE-2026-42824 CVE-2025-32711CVE-2025-32711
Target & Sectors
Global Scope
Incident Timeline
‎Jun 15, 2026
Attackers exploited a one-click exfiltration path by chaining three bugs into the Copilot Enterprise Search URL, allowing them to steal emails, files, and MFA codes.
organisation CVSS
Microsoft assigned CVE-2026-42824 and marked it critical; the CVSS scores ran lower and disagreed, 6.5 from Microsoft and 7.5 from the National Vulnerability Database .
organisation /Your_Security_Code_847291
The attacker reads it off their own logs, for example, a request for /Your_Security_Code_847291/img.png.
organisation CVE-2025-32711
The same pattern showed up in EchoLeak (CVE-2025-32711), the zero-click Copilot data-leak bug Aim Security disclosed in 2025.
organisation Aim Security
The same pattern showed up in EchoLeak (CVE-2025-32711), the zero-click Copilot data-leak bug Aim Security disclosed in 2025.
organisation SearchLeak
In practice, SearchLeak stacks one AI-specific weakness on two old web bugs, and each link is needed for the next.
organisation the Copilot Enterprise Search
The entry point is the q parameter in the Copilot Enterprise Search URL.
organisation Copilot
It is meant for a natural-language query, but Copilot reads whatever sits there as instructions, not just a search string.
organisation Next
Next is a race condition in how the response renders.
organisation Content Security Policy
The last link gets the data past the page's Content Security Policy.
organisation CSP
The CSP on m365.cloud.microsoft blocks images from arbitrary domains, but it allowlists *.bing.com.
organisation Copilot Enterprise
What an attacker gets Copilot Enterprise can reach whatever the signed-in user can, through their Microsoft Graph access, and the attacker inherits that reach without ever logging in.
organisation Microsoft Graph
What an attacker gets Copilot Enterprise can reach whatever the signed-in user can, through their Microsoft Graph access, and the attacker inherits that reach without ever logging in.
organisation MFA
The most time-sensitive prize sits in the inbox: one-time codes, MFA codes, and password-reset links, often still valid for a few minutes.
organisation SharePoint
The same access also reaches calendar invites, meeting notes, and any SharePoint or OneDrive file Copilot has indexed, where the salary data, earnings figures, and acquisition plans live.
organisation OneDrive
The same access also reaches calendar invites, meeting notes, and any SharePoint or OneDrive file Copilot has indexed, where the salary data, earnings figures, and acquisition plans live.
organisation Copilot Personal
Varonis researcher Dolev Taler demonstrated the same one-click technique in an earlier Reprompt attack against Copilot Personal, and it held up against Enterprise Search despite the extra guardrails that tier is supposed to enforce.
organisation HTML
Look for Copilot Search URLs carrying encoded payloads or HTML in the q parameter, and for unusual outbound requests to Bing's image endpoints.
‎2026/06/15
Attackers exploited a parameter-to-prompt (P2P) injection weakness in Microsoft 365 Copilot Enterprise Search to steal emails, files, and MFA codes by clicking on trusted links.
infrastructure Microsoft 365
One-Click Microsoft 365 Copilot Flaw Could Have Let Attackers Steal Emails, Files, and MFA Codes.
 Swati Khandelwal  Jun 15, 2026 Vulnerability / Enterprise Security A single click on a trusted Microsoft link could have let an attacker pull emails, calendar details, and indexed files out of Microsoft 365 Copilot Enterprise Search.
New attack turned Microsoft 365 Copilot into 1-click data theft tool.
A critical vulnerability chain dubbed SearchLeak in Microsoft 365 Copilot Enterprise could allow attackers to steal sensitive data from a target's mailbox, OneDrive, or SharePoint account through a specially crafted URL.
In the first stage, the attack exploits a parameter-to-prompt (P2P) injection weakness by leveraging how Microsoft 365 Copilot Search accepts the ‘q’ URL parameter for search queries.
The complete SearchLeak attack chain Source: Varonis When chaining the weaknesses, the attack starts with the victim clicking on a crafted link that launches Microsoft 365 Copilot Search with instructions in the 'q' parameter to search the victim’s mailbox or other data sources.
organisation MFA Codes
One-Click Microsoft 365 Copilot Flaw Could Have Let Attackers Steal Emails, Files, and MFA Codes.
organisation Vulnerability / Enterprise Security
 Swati Khandelwal  Jun 15, 2026 Vulnerability / Enterprise Security A single click on a trusted Microsoft link could have let an attacker pull emails, calendar details, and indexed files out of Microsoft 365 Copilot Enterprise Search.
organisation Microsoft
 Swati Khandelwal  Jun 15, 2026 Vulnerability / Enterprise Security A single click on a trusted Microsoft link could have let an attacker pull emails, calendar details, and indexed files out of Microsoft 365 Copilot Enterprise Search.
Microsoft addressed SearchLeak at the beginning of the month and assigned it the CVE-2026-42824 identifier with a maximum severity, critical rating.
organisation Microsoft 365 Copilot Enterprise Search
 Swati Khandelwal  Jun 15, 2026 Vulnerability / Enterprise Security A single click on a trusted Microsoft link could have let an attacker pull emails, calendar details, and indexed files out of Microsoft 365 Copilot Enterprise Search.
organisation Microsoft 365 Copilot
New attack turned Microsoft 365 Copilot into 1-click data theft tool.
organisation SharePoint
A critical vulnerability chain dubbed SearchLeak in Microsoft 365 Copilot Enterprise could allow attackers to steal sensitive data from a target's mailbox, OneDrive, or SharePoint account through a specially crafted URL.
organisation OneDrive
A critical vulnerability chain dubbed SearchLeak in Microsoft 365 Copilot Enterprise could allow attackers to steal sensitive data from a target's mailbox, OneDrive, or SharePoint account through a specially crafted URL.
organisation Microsoft 365 Copilot Enterprise
A critical vulnerability chain dubbed SearchLeak in Microsoft 365 Copilot Enterprise could allow attackers to steal sensitive data from a target's mailbox, OneDrive, or SharePoint account through a specially crafted URL.
organisation Microsoft 365 Copilot Search
In the first stage, the attack exploits a parameter-to-prompt (P2P) injection weakness by leveraging how Microsoft 365 Copilot Search accepts the ‘q’ URL parameter for search queries.
organisation SearchLeak
Microsoft addressed SearchLeak at the beginning of the month and assigned it the CVE-2026-42824 identifier with a maximum severity, critical rating.
organisation Copilot
Unlike regular Copilot, which generates content, Microsoft Copilot Enterprise Search looks for company data in emails, meetings, SharePoint files, and OneDrive.
organisation Microsoft Copilot Enterprise Search
Unlike regular Copilot, which generates content, Microsoft Copilot Enterprise Search looks for company data in emails, meetings, SharePoint files, and OneDrive.
organisation Next
Next, it then generates a response with an image tag, including the stolen information in the URL.
organisation CSP
They combined a parameter-to-prompt injection, an HTML rendering race condition, and a content-security-policy (CSP) bypass enabled by Bing server-side request forgery (SSRF).
organisation HTML
They combined a parameter-to-prompt injection, an HTML rendering race condition, and a content-security-policy (CSP) bypass enabled by Bing server-side request forgery (SSRF).
organisation Copilot Enterprise Search
The exfiltrated information could be email content (e.g., access codes, passwords), calendar events and meeting details, documents, and other content accessible through Copilot Enterprise Search.
organisation Bing’s “Search by Image
The third part of the chain is an SSRF issue in Bing’s “Search by Image” feature, which is used to launch a request to fetch an image from the attacker's endpoint.
organisation EDR
The Picus whitepaper shows how breach and attack simulation tests your SIEM and EDR rules so threats stop slipping by detection.
Tactical Metrics
Metrics
infrastructure
‎Microsoft 365
Affected Product
One-Click Microsoft 365 Copilot Flaw Could Have Let Attackers Steal Emails, Files, and MFA Codes.
 Swati Khandelwal  Jun 15, 2026 Vulnerability / Enterprise Security A single click on a trusted Microsoft link could have let an attacker pull emails, calendar details, and indexed files out of Microsoft 365 Copilot Enterprise Search.
New attack turned Microsoft 365 Copilot into 1-click data theft tool.
A critical vulnerability chain dubbed SearchLeak in Microsoft 365 Copilot Enterprise could allow attackers to steal sensitive data from a target's mailbox, OneDrive, or SharePoint account through a specially crafted URL.
In the first stage, the attack exploits a parameter-to-prompt (P2P) injection weakness by leveraging how Microsoft 365 Copilot Search accepts the ‘q’ URL parameter for search queries.
The complete SearchLeak attack chain Source: Varonis When chaining the weaknesses, the attack starts with the victim clicking on a crafted link that launches Microsoft 365 Copilot Search with instructions in the 'q' parameter to search the victim’s mailbox or other data sources.
Intelligence Sources
The Hacker News 2026-06-15
BleepingComputer 2026-06-15