Brief Summary: CVE-2026-41105 SSRF in Azure Monitor Action Group Notification System Enables Privilege Escalation

Introduction

A Server-Side Request Forgery flaw in the Azure Monitor Action Group Notification System could have allowed a low privileged, authenticated attacker to escalate privileges by forcing the service to issue unintended internal requests over the network. With Azure Monitor Action Groups widely used across enterprise environments for alert driven notifications via email, SMS, and webhooks, the blast radius of this SSRF was significant; Microsoft has already resolved it transparently on their infrastructure.

Technical Information

CVE-2026-41105 is classified under CWE-918 (Server-Side Request Forgery). The vulnerable component is the Azure Monitor Action Group Notification System, which handles the delivery of notifications triggered by Azure Monitor alerts. This includes email, SMS, webhook, and other notification channels.

CVSS Breakdown

The CVSS 3.1 base score is 8.1, with the vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Breaking this down:

The scoring tells us this is a vulnerability that enables significant unauthorized data access and modification, but does not allow an attacker to disrupt the service itself.

Root Cause and Attack Flow

The root cause is a Server-Side Request Forgery condition in the notification system. In SSRF vulnerabilities, the server can be tricked into making HTTP requests to destinations controlled or influenced by the attacker. In this case, an authorized user with low privileges could craft requests that caused the Azure Monitor Action Group Notification System to issue unintended internal requests. By pivoting through the trusted server component, the attacker could potentially reach internal resources or services that would otherwise be inaccessible at their privilege level, effectively escalating their privileges.

The attack flow, based on the CVSS metrics and vulnerability description, follows a pattern common to cloud service SSRF:

1. The attacker authenticates to the Azure environment with low privilege credentials.
2. The attacker crafts a request to the Action Group Notification System that includes or influences a URL or endpoint parameter.
3. The notification system processes this request and initiates a server-side HTTP call to the attacker-specified destination.
4. Because the request originates from a trusted internal service, it bypasses network-level access controls, granting the attacker access to internal resources or metadata endpoints.
5. The attacker leverages this access to read confidential data or modify resources beyond their authorized scope.

The high confidentiality and high integrity impact ratings confirm that successful exploitation could yield both unauthorized data access and the ability to tamper with resources.

Patch Information

This is a cloud-hosted vulnerability, meaning there is no customer-deployable update. The vulnerable component lives entirely within Microsoft's cloud infrastructure, and Microsoft resolved the issue with a server-side fix applied transparently before the CVE was published.

The MSRC advisory explicitly states: "This vulnerability has already been fully mitigated by Microsoft. There is no action for users of this service to take."

Key details about the remediation:

The CVE was published on May 7, 2026, purely for transparency purposes. This aligns with Microsoft's broader initiative described in their "Toward greater transparency: Unveiling Cloud Service CVEs" program, where they now disclose CVEs for cloud service vulnerabilities even when the fix has already been deployed.

If your organization uses Azure Monitor Action Groups for sending email, SMS, webhook, or other alert-triggered notifications, the underlying SSRF weakness has already been patched on Microsoft's side. No configuration changes, agent updates, or redeployments are required.

Affected Systems and Versions

The Security Update Guide lists a single affected product: Azure Monitor Action Group notification system. This is a cloud-hosted service component, so traditional version numbers or build identifiers do not apply. Any organization using Azure Monitor Action Groups for alert notifications was potentially in scope prior to Microsoft's server-side remediation.

Vendor Security History

Microsoft operates the Microsoft Security Response Center (MSRC) to investigate and disclose vulnerabilities across its product portfolio. The company holds approximately 20 percent of the worldwide cloud infrastructure market according to Synergy Research Group, placing it as the second largest cloud provider globally. Given this footprint, vulnerabilities in Azure services carry broad potential impact across enterprise environments.

Microsoft recently launched an initiative to publish CVEs for cloud services even when no customer action is required. CVE-2026-41105 is a direct product of this transparency program. The goal is to keep the security community informed about threats that have been mitigated, rather than silently patching and leaving defenders unaware. This is a welcome shift; historically, cloud-side vulnerabilities were often resolved without public disclosure, leaving security teams with incomplete visibility into the threat landscape affecting their infrastructure.

References

• NVD Entry for CVE-2026-41105
• Microsoft Security Update Guide: CVE-2026-41105
• Tenable: CVE-2026-41105
• Microsoft Security Response Center: Security Update Guide
• Microsoft MSRC Blog: Toward Greater Transparency: Unveiling Cloud Service CVEs
• OWASP: Server Side Request Forgery
• Synergy Research Group: Cloud Market Share Trends
• CISA Known Exploited Vulnerabilities Catalog