What is CVE-2026-66803?

CVE-2026-66803 is a critical-severity vulnerability in Microsoft Azure Cosmos Db, classified under Improper Access Control. CVSS score: 10.0/10. Published 2026-07-30.

How severe is CVE-2026-66803?

Critical severity. CVSS v3 base score is 10.0 out of 10.

Vulnerability in Microsoft Azure Cosmos Db

CVE-2026-66803

Improper access control in Azure Cosmos DB allows an unauthorized attacker to execute code over a network.

EPSS: 0.005 (44.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Microsoft Azure Cosmos Db
Microsoft Azure_cosmos_db

Weakness classification (CWE)

CWE-284 — Improper Access Control

References

Azure Cosmos DB Remote Code Execution Vulnerability (vendor-advisory, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-66803?: CVE-2026-66803 is a critical-severity vulnerability in Microsoft Azure Cosmos Db, classified under Improper Access Control. CVSS score: 10.0/10. Published 2026-07-30.
How severe is CVE-2026-66803?: Critical severity. CVSS v3 base score is 10.0 out of 10.