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. Enterprises widely use Azure Monitor Action Groups for alert-driven notifications by email, SMS, and webhook, so the blast radius of this SSRF was significant. Microsoft has already resolved it transparently on its own 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 delivers the notifications that Azure Monitor alerts trigger over email, SMS, webhook, and other 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. Metric by metric:

Taken together, the scores describe a vulnerability that allows significant unauthorized data access and modification but does not let an attacker disrupt the service itself.

Root Cause and Attack Flow

The root cause is a Server-Side Request Forgery condition in the notification system. In an SSRF, an attacker can trick the server into making HTTP requests to destinations the attacker controls or influences. Here, 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 that trusted server component, the attacker could reach internal resources or services that would otherwise be out of reach at their privilege level, which in effect escalates their privileges.

Going by the CVSS metrics and the vulnerability description, the attack flow follows a pattern common to SSRF in cloud services:

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 the request and makes a server-side HTTP call to the attacker-specified destination.
4. Because the request comes from a trusted internal service, it bypasses network-level access controls and gives the attacker access to internal resources or metadata endpoints.
5. The attacker uses 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 give the attacker both unauthorized data access and the ability to tamper with resources.

Patch Information

This is a cloud-hosted vulnerability, so 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 states: "This vulnerability has already been fully mitigated by Microsoft. There is no action for users of this service to take."

Remediation details:

Microsoft published the CVE on May 7, 2026, purely for transparency. The disclosure fits Microsoft's broader "Toward greater transparency: Unveiling Cloud Service CVEs" program, under which the company now discloses CVEs for cloud service vulnerabilities even when the fix has already been deployed.

If your organization uses Azure Monitor Action Groups to send email, SMS, webhook, or other alert-triggered notifications, Microsoft has already patched the underlying SSRF weakness on its side. You do not need to change any configuration, update any agents, or redeploy anything.

Affected Systems and Versions

The Security Update Guide lists a single affected product: Azure Monitor Action Group notification system. Because this is a cloud-hosted service component, traditional version numbers and build identifiers do not apply. Any organization using Azure Monitor Action Groups for alert notifications was potentially in scope before Microsoft applied its server-side fix.

Vendor Security History

Microsoft runs the Microsoft Security Response Center (MSRC), which investigates and discloses vulnerabilities across the company's products. According to Synergy Research Group, Microsoft holds approximately 20 percent of the worldwide cloud infrastructure market, which makes it the second-largest cloud provider in the world. With a footprint that size, a vulnerability in an Azure service can have broad impact across enterprise environments.

Microsoft recently started publishing CVEs for cloud services even when customers have no action to take, and CVE-2026-41105 is a direct product of that transparency program. The goal is to tell the security community about threats that have been mitigated, instead of patching silently and leaving defenders unaware. This is a welcome shift. Cloud-side vulnerabilities used to be resolved without public disclosure in many cases, which left security teams with an incomplete view of the threats 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