Full Report
Microsoft has patched a maximum-severity vulnerability in the Entra ID identity and access management (IAM) platform that has been exploited in attacks. [...]
Analysis Summary
# Vulnerability: Critical Deserialization RCE in Microsoft Entra ID
## CVE Details
- **CVE ID:** CVE-2026-69836
- **CVSS Score:** 10.0 (Critical)
- **CWE:** CWE-502 (Deserialization of Untrusted Data)
## Affected Systems
- **Products:** Microsoft Entra ID (formerly Azure Active Directory)
- **Versions:** All cloud-based versions prior to the August 2026 mitigation.
- **Configurations:** This was a platform-side vulnerability affecting the cloud-based Identity and Access Management (IAM) service used by Microsoft 365, Azure, and Dynamics CRM Online.
## Vulnerability Description
The flaw stems from the insecure deserialization of untrusted data within the Entra ID platform. An unauthorized, unauthenticated attacker could send specially crafted data over the network to the service. When the platform processes this data, it triggers the execution of arbitrary code within the context of the Entra ID environment.
## Exploitation
- **Status:** Exploited in the wild (per Microsoft's advisory and reporting).
- **Complexity:** Low
- **Attack Vector:** Network
- **PoC Availability:** Not currently available online.
## Impact
- **Confidentiality:** Total (Full access to identity data and tenant resources).
- **Integrity:** Total (Ability to modify identity policies and permissions).
- **Availability:** Total (Potential for platform-wide service disruption).
## Remediation
### Patches
- **Fully Mitigated:** Microsoft has applied a backend patch to the Entra ID service. Since Entra ID is a SaaS (Software as a Service) platform, the fix was deployed automatically by the vendor.
### Workarounds
- **No Action Required:** There are no manual configuration changes or workarounds necessary for end-users or administrators, as the fix was applied at the infrastructure level.
## Detection
- **Indicators of Compromise:** Users should review Entra ID (Azure AD) sign-in logs and audit logs for unusual service principal activity or unauthorized configuration changes.
- **Detection methods and tools:** Organizations should utilize Microsoft Sentinel or similar SIEM tools to monitor for "Anomalous Token" alerts or "Unusual Volume of External Identity Additions" which may indicate post-exploitation activity.
## References
- **Microsoft Security Advisory:** hxxps[://]msrc[.]microsoft[.]com/update-guide/vulnerability/CVE-2026-69836
- **NVD Entry:** hxxps[://]nvd[.]nist[.]gov/vuln/detail/CVE-2026-69836
- **Technical Coverage:** hxxps[://]www[.]bleepingcomputer[.]com/news/microsoft/microsoft-warns-of-max-severity-entra-id-flaw-exploited-in-attacks/