External risk intelligence

Microsoft Dataverse Authentication Bypass Vulnerability

CVE advisorySeverity: HIGH (CVSS 8.1)

CVE-2026-77903

Microsoft Dataverse is a cloud-based data platform frequently used to power internet-facing applications, APIs, and business service portals, making it commonly accessible via network connections in standard enterprise and cloud-native deployments.

Authentication Bypass

Microsoft Dataverse

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

An authentication bypass vulnerability in Microsoft Dataverse could allow an attacker to gain unauthorized privileges over a network. This technology is often used to support internet-facing applications and business services, increasing the potential for exposure. The primary concern is to confirm if your organization utilizes this specific Microsoft product and to what extent.

  • Bypass login to gain unauthorized access.
  • Potential for privilege escalation by attackers.
  • Confirm if this impacts your organization.

Attack Path

How an attacker could exploit the issue

An attacker could potentially bypass authentication to gain unauthorized access and elevate their privileges within Microsoft Dataverse. This could occur over a network, requiring a degree of technical skill to spoof authentication. Successful exploitation might allow an attacker to perform actions they are not normally permitted to, potentially impacting data integrity and availability.

  • Requires network access.
  • Spoofs authentication to bypass checks.
  • Unauthorized privilege escalation.

Live Threat

Current exploitation, exposure, and threat context

An attacker could bypass authentication in Microsoft Dataverse, potentially leading to unauthorized privilege escalation over a network. This could affect system data and service behavior when supported by the advisory.

  • System data and service behavior.
  • Bypass authentication over a network.
  • Unauthorized privilege escalation.

Operational Fix

Recommended remediation, mitigation, and detection steps

Determining ownership of this authentication bypass vulnerability in Microsoft Dataverse requires coordination between application owners who rely on the platform and the infrastructure or platform teams managing its deployment. The first practical step is to identify all Dataverse instances, confirm their network exposure, and assess business criticality to prioritize remediation efforts.

  • Application and platform teams own the issue.
  • Verify Dataverse instance exposure and criticality.
  • Plan coordinated remediation based on risk.

Supplementary metadata

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Frequently asked questions

What is Microsoft Dataverse used for?

Microsoft Dataverse is a cloud-based data platform that serves as a central storage and management hub for business data. It provides the backend infrastructure for custom applications, power-driven business processes, and service portals, often connecting various organizational tools to share and secure information.

How does this CVE-2026-77903 vulnerability work?

This flaw is classified as Authentication Bypass by Spoofing (CWE-290). In simple terms, it means the system can be tricked into accepting a fake identity. An attacker exploits this to bypass standard login checks, effectively fooling the software into granting them elevated privileges as if they were an authorized user.

What triggers this authentication bypass?

The vulnerability is triggered when an attacker successfully spoofs authentication data over a network connection. It does not occur through normal user activity; it requires a deliberate, malicious effort to craft the spoofed request. A valid user performing standard business tasks within the platform will not inadvertently trigger this security weakness.

Is my organization at risk from CVE-2026-77903?

Halo Surface Signal indicates that Dataverse is frequently used for internet-facing applications, making it accessible via network connections. If your organization hosts portals or services on this platform that are reachable over the internet, the risk level is higher. You should prioritize internal systems that serve as the backbone for public-facing business services.

What should I do if I use Microsoft Dataverse?

Start by identifying all instances of Dataverse within your environment and mapping which ones are accessible over the network. Coordinate with your application and infrastructure teams to verify if your specific configurations are impacted, then assess the business criticality of those services to plan appropriate updates or security adjustments.

References