Overview
- Microsoft publicly flagged CVE-2026-69836 as a deserialization vulnerability in Entra ID that allowed unauthorized remote code execution.
- The company credited principal security engineer Robert Fitzaptrick for reporting the bug and said it has applied a server-side mitigation so customers do not need to take steps.
- Microsoft acknowledged the flaw was exploited in the wild but provided no technical details about how attackers used the bug, when exploitation began, or whether the activity is ongoing.
- The flaw matters because Entra ID controls authentication for Microsoft 365 and Azure services, and a successful compromise can give attackers broad access to cloud resources.
- The disclosure follows other recently exploited Microsoft bugs, including a patched Windows zero-day tied to the Lazarus Group, and raises risks that exploit code or further details could emerge and affect tenants.